CN103073708A - Method for preparing high molecular weight polylactic acid stereoblock copolymer - Google Patents
Method for preparing high molecular weight polylactic acid stereoblock copolymer Download PDFInfo
- Publication number
- CN103073708A CN103073708A CN2013100205721A CN201310020572A CN103073708A CN 103073708 A CN103073708 A CN 103073708A CN 2013100205721 A CN2013100205721 A CN 2013100205721A CN 201310020572 A CN201310020572 A CN 201310020572A CN 103073708 A CN103073708 A CN 103073708A
- Authority
- CN
- China
- Prior art keywords
- segmented copolymer
- poly
- plla
- polylactic acid
- high molecular
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention belongs to the technical field of high molecular materials, in particular to a method for preparing a high molecular weight polylactic acid stereoblock copolymer. According to the invention, the method comprises the following steps: by taking metal carboxylate or metal alkoxide as an hydroxyl-terminated activator, carrying out activating reaction on poly-L-lactic acid (poly-R-lactic acid) or a poly-L-lactic acid (poly-R-lactic acid) segmented copolymer so as to prepare a high-activity polymer capped with a specific functional group; and then using the high-activity polymer capped with the specific functional group as a macroinitiator so as to initiate ring opening of a R-lactide (L-lactide) monomer at a comparatively lower reaction temperature by using a ring-opening polymerization mechanism so as to successfully prepare the high molecular weight polylactic acid stereoblock copolymer. According to the invention, the weight-average molecular weight of the prepared high molecular weight polylactic acid stereoblock copolymer is high up to 370000; moreover, the prepared high molecular weight polylactic acid stereoblock copolymer has the advantages of controllable molecular structure, high stereoregularity, good heat resistance and broad application prospect.
Description
Technical field
The invention belongs to technical field of polymer materials, be specifically related to a kind of synthetic method for preparing the polylactic acid stereoscopic segmented copolymer of high molecular.
Background technology
Poly(lactic acid) (PLA) is a kind of green plastic that is prepared from take reproducible plant resources as raw material, has good biodegradability.Therefore, the PLA material has vast potential for future development, is used widely in fields such as bio-medical, bio-pharmaceuticals and food product pack, and its research and production get most of the attention.
But, to compare with general petroleum product material, the cost of PLA is high, poor heat resistance, the problem such as processing characteristics is relatively poor has greatly limited its Application Areas, particularly in the application in engineering materials field.Main degree of crystallinity, blending technology, radiation crosslinking technology and the nanometer composite technology etc. that improve poly(lactic acid) of adopting come PLA is carried out modification at present, but the product over-all properties that obtains is not good.
Utilize the rotational isomerism characteristic of poly-lactic acid material, with PLLA (PLLA) and poly-dextrolactic acid (PDLA) blend, the fusing point of the Stereocomplex poly(lactic acid) (sc-PLA) for preparing can reach 230
oC exceeds 50 than the fusing point of homopolymer separately
oC, resistance toheat (Macromolecules, 20 (1987): 904-906) that can effectively improve poly(lactic acid).The Stereocomplex poly-lactic acid material has the biodegradable polymers engineering materials of practical prospect as a class, is one of material of paying close attention to the most in biodegradable polymer investigation of materials field of home and abroad investigator.
About the existing many reports of the preparation method of sc-PLA.Mainly concentrate on two kinds of method: PLLA and PDLA according to 1/1 blend; Preparation contains the stereoblock poly(lactic acid) (sb-PLA) of PLLA and PDLA segment, utilizes PLLA and the intersegmental approach effect of PDLA chain, so that they can reach the compatible of molecular scale, generates the high sc-PLA crystal of purity.
Patent CN102532837A discloses a kind of preparation method of polylactic acid stereoscopic composite of high molecular.The method be with PLLA and poly-dextrolactic acid by Different Weight than mixing, and with mixture in torque rheometer 140 ~ 210
oMelt-mixing under the C condition has been finished the preparation of the polylactic acid stereoscopic composite of high molecular.Yet, when adopting above melt or solution blended process to prepare sc-PLA, because the intersegmental consistency of PLLA and PDLA chain is relatively poor, particularly particularly evident for the poly(lactic acid) of high molecular, be accompanied by when generating sc-PLA, very easily generate PLLA and PDLA homopolymer crystal, and the molecular structure of the sc-PLA that obtains be uncontrollable, have a strong impact on thermomechanical property (Macromolecules, 40 (2007): 1049-1054) of goods.
Preparation sb-PLA mainly adopts process for solid state polycondensation, stereoselective polymerization method and three kinds of methods of ring-opening polymerization method.Patent CN 101712763A discloses the preparation method of a kind of sb-PLA, namely adopts above process for solid state polycondensation, 180 ~ 200
oUnder the C thermal treatment temp, prepared weight-average molecular weight and be 8 ~ 280,000 sb-PLA.But when adopting this process for solid state polycondensation to prepare sb-PLA, thermal treatment temp is usually 160
oC ~ 200
OC, this moment, the side reactions such as thermal destruction and transesterify easily occured in low-molecular-weight poly(lactic acid), so that react uncontrollable, the tacticity of the sb-PLA for preparing is not high.
In addition, when adopting the standby sb-PLA of stereoselective polymerization legal system, need to use expensive catalyzer, and the molecular weight of the sb-PLA of preparation generally is lower than 20,000, do not have practical value.Comparatively speaking, the ring-opening polymerization method is a kind of have development prospect and feasible method of implementation industrialization, and its adopts metal carboxylate or the metal alkoxide that cheaply is easy to get, the reaction proceed step by step.Particularly after Kimura optimizes improvement, can successfully prepare number-average molecular weight up to 100,000 and the relatively high sb-PLA(Journal of Polymer Science:Part A:Polymer Chemistry of tacticity, 48 (2010): 794-801).But also there is defective in this modification.In its secondary ring-opening polymerization, be to guarantee the generation of chain starting reaction, usually need relatively high temperature of reaction, for example 190
oC, and under this temperature, usually can follow the generation of the side reactions such as the thermal destruction of polylactic acid molecule chain and transesterify, thus the further raising of restriction sb-PLA polymericular weight and tacticity.In addition, when the number-average molecular weight of the macromole evocating agent that participates in the secondary ring-opening polymerization surpasses 50,000, can not effectively cause the with it lactide monomer open loop of corresponding rotational isomerism, and often be accompanied by the generation of side reaction, such as homopolymer generation and chain transfer reaction etc., cause the chemical structure of the sb-PLA for preparing uncontrollable, also further limited raising (Macromolecular Chemistry and Physics, 213 (2012): 695-704) of its molecular weight.
Summary of the invention
The object of the present invention is to provide a kind of method for preparing the polylactic acid stereoscopic segmented copolymer of high molecular, the defective that exists to overcome the existing synthetic technology of appeal.
The method of the polylactic acid stereoscopic segmented copolymer of preparation high molecular provided by the invention, adopt kind of a terminal hydroxy group activating technology, poly-left-handed (dextrorotation) lactic acid or poly-left-handed (dextrorotation) lactic acid block copolymer of chain end being contained hydroxyl carry out the terminal hydroxy group activating pretreatment, prepare the highly reactive polymer of particular functional group's end-blocking.Then, as macromole evocating agent, cause dextrorotation (left-handed) lactide monomer generation ring-opening polymerization with this highly reactive polymer, prepare the polylactic acid stereoscopic segmented copolymer of high molecular.Specifically may further comprise the steps:
(1) under anhydrous condition and protection of inert gas, to gather left-handed (dextrorotation) lactic acid or gather left-handed (dextrorotation) lactic acid block copolymer and be dissolved in the organic solvent, add metal carboxylate or metal alkoxide and carry out priming reaction as the polymer end hydroxy activating reagent, obtain the highly reactive polymer of particular functional group's end-blocking;
(2) with above-mentioned highly reactive polymer and dextrorotation (left-handed) lactide monomer generation ring-opening polymerization, obtain the polylactic acid stereoscopic segmented copolymer of high molecular.
In the step (1), the number-average molecular weight of described poly-left-handed (dextrorotation) lactic acid or poly-left-handed (dextrorotation) lactic acid block copolymer is 3 ~ 100,000.
In the step (1), described poly-left-handed (dextrorotation) lactic acid and poly-left-handed (dextrorotation) lactic acid block copolymer are if linear polymer, require to have in its polymer molecular chain and a hydroxyl is only arranged as end group, and can only be the terminal group of polylactic acid chain segment; Described poly-left-handed (dextrorotation) lactic acid block copolymer also can be star block copolymer, preferably is one or more of three cladodification polyoxypropylenes-poly-left-handed (dextrorotation) lactic acid.
In the step (1), described organic solvent preferably is one or more in toluene, dimethylbenzene, dichlorobenzene, the phenyl ether.The add-on of described organic solvent is generally poly-left-handed (dextrorotation) lactic acid or poly-left-handed (dextrorotation) lactic acid block copolymer quality 2 ~ 5 times.
In the step (1), described terminal hydroxy group activator metal carboxylate salt or metal alkoxide preferably are one or more in the inferior tin of stannous octoate, aluminum isopropylate, stannous acetate and lactic acid.
In the step (1), the mass ratio of described poly-left-handed (dextrorotation) lactic acid or poly-left-handed (dextrorotation) lactic acid block copolymer and terminal hydroxy group activator is (8 ~ 15): 1.
In the step (1), described temperature of reaction is 50 ~ 60
oC, the described reaction times is 4 ~ 6 hours.
In the step (2), the amount ratio of described highly reactive polymer and dextrorotation (left-handed) rac-Lactide is preferably mass ratio and is (0.5 ~ 1.5): 1 for making described polylactic acid stereoscopic segmented copolymer reach its molecular weight.
In the step (2), described ring-opening polymerization is preferably body ring-opening polymerization method.Described reaction is carried out under oxygen free condition, and the vacuum tightness of reaction system is preferably 0.1 Pa ~ 100 Pa; Described temperature of reaction is preferably 120 ~ 160
oC; The described reaction times is as the criterion to reach described molecular weight of product, is generally 24 ~ 72 hours.
The invention has the advantages that:
(1) compared with prior art, the invention solves the ring-opening polymerization method and can not cause number-average molecular weight and surpass 50,000 poly-left-handed (dextrorotation) lactic acid or gather left-handed (dextrorotation) lactic acid block copolymer generation polymerization, prepare the technical barrier of the polylactic acid stereoscopic segmented copolymer that molecular structure is controlled and molecular weight is high.
(2) the present invention can carry out real-time monitoring to the chemical structure of product by the feed ratio of manual control reactant.
(3) the ring-opening polymerization temperature described in the present invention is 120 ~ 160
oC has avoided the generation of the side reactions such as the generation thermal destruction of polylactic acid molecule chain and transesterify under this cold condition, the tacticity of the product for preparing is higher.
The weight-average molecular weight of the polylactic acid stereoscopic segmented copolymer that the present invention prepares is up to 370,000, and its molecular structure is controlled, stereoregular is high, good heat resistance, has broad application prospects.
Description of drawings
Fig. 1 is the proton nmr spectra of the highly reactive polymer (B) of the embodiment of the invention 1 middle-end hydroxy activating reagent stannous octoate (A) and Sn (Oct) end-blocking.
Fig. 2 is the ground substance assistant laser Dissociative adsorption flight time mass spectrum spectrogram of the highly reactive polymer (B) of three cladodification polyoxypropylene in the embodiment of the invention 1-D-polylactic-acid block copolymer (A) and Sn (Oct) end-blocking.
Fig. 3 is the proton nmr spectra of three cladodification polyoxypropylene in the embodiment of the invention 1-D-poly(lactic acid)-PLLA stereoblock copolymer.
Fig. 4 is the partial enlarged drawing of the carbon-13 nmr spectra of three cladodification polyoxypropylene in the embodiment of the invention 1-D-poly(lactic acid)-PLLA stereoblock copolymer.
Fig. 5 is the DSC spectrogram of three cladodification polyoxypropylene in the embodiment of the invention 1-D-poly(lactic acid)-PLLA stereoblock copolymer.
Embodiment
The present invention is further described with embodiment for the below, but the present invention is not limited, and the raw material among the embodiment is conventional commercially available prod, wherein:
The molecular weight of poly-left-handed (dextrorotation) lactic acid that the present invention uses or poly-left-handed (dextrorotation) lactic acid block copolymer is measured by gel permeation chromatograph (GPC), chemical constitution pass through proton nmr spectra (
1HNMR) determine.Utilize among the present invention the molecular structure of the high reactivity macromole salt performed polymer that the terminal hydroxy group activating technology prepares and terminal group structure can by proton nmr spectra (
1HNMR) and ground substance assistant laser Dissociative adsorption flight time mass spectrum (MALDI-TOF MS) conclusive evidence.The polylactic acid stereoscopic segmented copolymer of the present invention's preparation is measured its molecular weight and distribution thereof by gel permeation chromatograph (GPC), proton nmr spectra (
1HNMR) determine its chemical constitution, the specific rotatory power method calculates the ratio of D-LA or L-LA content and then infers its chemical structure, carbon-13 nmr spectra (
13C NMR) determine its tacticity, dsc (DSC) is measured its thermal characteristics.
(1) taking by weighing the 5.05g number-average molecular weight is 3.3 ten thousand three cladodification polyoxypropylene-D-polylactic-acid block copolymer (PPO-PDLA) and 0. 36g stannous octoate, is dissolved in the 100ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the L-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 4.6g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 100Pa, and 130 ℃ of temperature of reaction were reacted 72 hours, namely obtain the polyoxypropylene of three cladodification-D-poly(lactic acid)-PLLA (PPO-PDLA-PLLA) stereoblock copolymer, its molecular structure is shown in molecular formula among Fig. 3.Products therefrom is purified, and it is 130,000 that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 47.8%.
Fig. 1 is the proton nmr spectra of the highly reactive polymer (B) of terminal hydroxy group activator stannous octoate (A) and Sn (Oct) end-blocking, and the chemical shift ownership of each proton as shown in the figure.Wherein, two-CH in the stannous octoate
3Appear at respectively 0.9 and 2.25 ppm with the chemical shift of one-CH; With-two-CH that CH links to each other
2Chemical shift be 1.5-1.6 ppm, remaining two-CH
2Chemical shift be 1.3 ppm.The integral area value at corresponding these four peaks is 6:1:4:4 just, shows that the purity of the stannous octoate of selecting among the present invention is higher, can be directly used in priming reaction.Shown in Fig. 1 (B) partial enlarged drawing, have at the 4.36ppm place obvious proton peak be attributed to the polylactic acid chain end-chemical shift that CH is corresponding; Occurred in the position of 0.9 ppm and 2.25-2.35 ppm on the stannous octoate-CH
3With-CH proton peak, and the integral area at three peaks is 1:6:1, and this shows that terminal hydroxy group activating technology of the present invention can reach the activation efficiency of 100 %.
In addition, the chemical shift of methyl H appears at 1.14ppm(h on the propylene oxide repeating unit), methyl H appears at 1.60ppm(f on the lactic acid repeating unit) locate, on the propylene oxide repeating unit on methyne and the methylene radical H respectively at 3.40ppm(i) and 3.55ppm(g) obvious fignal center is arranged, methyne H is at 5.16ppm(e on the lactic acid repeating unit) located very significantly fignal center.Integral area by each peak can be 1:9 in the hope of the mass ratio of three cladodification propylene oxide polyethers and D-poly(lactic acid) in the segmented copolymer, and is consistent with the result of GPC.
After adopting GPC that the highly reactive polymer of PPO-PDLA and Sn (Oct) end-blocking is carried out classification, carry out MALDI-TOF MS test.MALDI-TOF MS test result as shown in Figure 2, any two peak-to-peak intervals all are 72 in two spectrograms of the highly reactive polymer of PPO-PDLA and Sn (Oct) end-blocking, just in time are the molecular weight of lactic acid repeating unit.In mass spectrum, each peak is representing the polymer molecule of a fixed member amount.PPO-PDLA contain the PO repeating unit (
=58), the LA repeating unit (
=72.06), three oh groups (
=17.02) and sodium ion (
=22.99), its any one PPO-PDLA macromolecular weight is
(PPO-PDLA)=58 * 3m+72.06 * 3n+17.02 * 3+22.99 * 3.If activate successfully, three oh groups of its corresponding highly reactive polymer can be by O-SnOct(
=261) successfully replace, at this moment
(highly reactive polymer)=58 * 3m+72.06 * 3n+261 * 3+22.99 * 3, its molecular weight increases by 732.Partial enlarged drawing from Fig. 2 as seen, highly reactive polymer namely adopts this terminal hydroxy group activating technology all with the O-SnOct end-blocking, can reach 100% activation rate.
Fig. 3 is the proton nmr spectra of three cladodification polyoxypropylene-D-poly(lactic acid)-PLLA stereoblock copolymer, and the chemical shift ownership of each proton as shown in the figure.Integral area by each peak can be 1:9:9 in the hope of the mass ratio of three cladodification propylene oxide polyethers, D-poly(lactic acid) and PLLA in the segmented copolymer, and the result who calculates with GPC result and specific rotatory power is consistent.
Fig. 4 is the carbon-13 nmr spectra of three cladodification polyoxypropylene-D-poly(lactic acid)-PLLA stereoblock copolymer.At CDCl
3In the HFIP mixed solvent, for the LA unit, the chemical shift of its carbonylic carbon atom appears at 170.42ppm(a) and 170.21ppm(a ') locate, correspond respectively to the mmmmm of six unit sequences, rmmmm, mmmmr and mmmrm structure show that the tacticity of three cladodification PPO-PDLA-PLLA stereoblock poly(lactic acid) is very high.And in the process of synthetic sb-PLA, often be accompanied by the generation of transesterification reaction, and causing racemize structure sequence unit to occur, obvious characteristic peak namely appears at 170.01 ppm places.The three cladodification PPO-PDLA-PLLA stereoblock poly(lactic acid) that adopt the terminal hydroxy group activating technology to prepare occur without characteristic peak at 170.01 ppm places, this shows highly reactive polymer and L-LA monomer generation ring-opening polymerization, and the tacticity of the three cladodification PPO-PDLA-PLLA that prepare is very high.
Fig. 5 is the DSC spectrogram of three cladodification polyoxypropylene-D-poly(lactic acid)-PLLA stereoblock copolymer.When copolymer sample 230
oThe C isothermal is in the time of three minutes, and the Stereocomplex crystal that PLLA and D-polylactic acid chain segment form is destroyed fully, and quenching obtains the structure of random coil.Under the temperature rise rate of 10 ℃/min, it is 206 ℃ that DSC records its fusing point, as shown in Figure 5.
(1) taking by weighing the 7.65g number-average molecular weight is 4.5 ten thousand three cladodification PPO-PDLA segmented copolymers and 0.77g stannous octoate, is dissolved in the 120ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4.5 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the L-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 7.0g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 75Pa, and 130 ℃ of temperature of reaction were reacted 72 hours, namely obtain the propylene oxide polyethers of three cladodification-D-poly(lactic acid)-PLLA (PPO-PDLA-PLLA) stereoblock copolymer, its molecular structure is shown in molecular formula among Fig. 3.Products therefrom is purified, and it is 16.5 ten thousand that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 49.2%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of three cladodification polyoxypropylenes, PLLA, D-poly(lactic acid) is 1:12:12 in the segmented copolymer; 198 ℃ of fusing points.
(1) taking by weighing the 5.5g number-average molecular weight is 5.2 ten thousand three cladodification PPO-PDLA segmented copolymers and 0.60g stannous octoate, is dissolved in the 100ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4.5 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the D-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 5.2g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 50Pa, and 140 ℃ of temperature of reaction were reacted 72 hours, namely obtain three cladodification polyoxypropylene-D-poly(lactic acid)-PLLA (PPO-PDLA-PLLA) stereoblock copolymer, its molecular structure is shown in molecular formula among Fig. 3.Products therefrom is purified, and it is 200,000 that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 50.5%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of three cladodification propylene oxide polyethers, PLLA, D-poly(lactic acid) is 1:15:15 in the segmented copolymer; 199 ℃ of fusing points.
(1) taking by weighing the 5.5g number-average molecular weight is 9.8 ten thousand three cladodification PPO-PDLA segmented copolymers and 0.68g stannous octoate, is dissolved in the 140ml dry toluene.Logical nitrogen, control temperature 60 C reaction 6 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the L-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 5.4g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 0.1Pa, and 140 ℃ of temperature of reaction were reacted 72 hours, namely obtain the polyoxypropylene of three cladodification-D-poly(lactic acid)-PLLA (PPO-PDLA-PLLA) stereoblock copolymer, its molecular structure is shown in molecular formula among Fig. 3.Products therefrom is purified, and it is 370,000 that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 51.5%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of three cladodification propylene oxide polyethers, PLLA, D-poly(lactic acid) is 1:23:23 in the segmented copolymer; 201 ℃ of fusing points.
(1) taking by weighing the 5.5g number-average molecular weight is 6.1 ten thousand linear PLLA PLLA and 0.62g stannous octoate, is dissolved in the 100ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the D-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 5.5g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 20Pa, 130 ℃ of temperature of reaction were reacted 72 hours, namely obtained linear PLLA-D-poly(lactic acid) (PDLA-PLLA) stereoblock copolymer.Products therefrom is purified, and it is 23.5 ten thousand that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 50.5%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of PLLA and D-poly(lactic acid) is 1:1 in the segmented copolymer; 215 ℃ of fusing points.
(1) taking by weighing the 6.0g number-average molecular weight is 3.5 ten thousand linear polyethylene glycol-PLLA segmented copolymer (PEG-PLLA) and 0.52g stannous octoate, is dissolved in the 100ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the D-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 5.1g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 70Pa, 130 ℃ of temperature of reaction were reacted 72 hours, namely obtained linear polyethylene glycol-PLLA-D-poly(lactic acid) (PEG-PLLA-PDLA) stereoblock copolymer.Products therefrom is purified, and it is 12.2 ten thousand that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 50.8%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of polyoxyethylene glycol, PLLA and D-poly(lactic acid) is 1:6:6 in the segmented copolymer; 201 ℃ of fusing points.
(1) taking by weighing the 6.1g number-average molecular weight is 6.4 ten thousand linear polyethylene glycol-PLLA segmented copolymer (PEG-PLLA) and 0.65g stannous octoate, is dissolved in the 100ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4 hours.After reaction finished, suction filtration was removed unreacted stannous octoate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the D-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 5.7g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 45Pa, 130 ℃ of temperature of reaction were reacted 72 hours, namely obtained linear polyethylene glycol-PLLA-D-poly(lactic acid) (PEG-PLLA-PDLA) stereoblock copolymer.Products therefrom is purified, and it is 22.5 ten thousand that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 50.1%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of polyoxyethylene glycol, PLLA and D-poly(lactic acid) is 1:12:12 in the segmented copolymer; 199 ℃ of fusing points.
Embodiment 8
(1) taking by weighing the 7.65g number-average molecular weight is 4.5 ten thousand three cladodification PPO-PLLA segmented copolymers and 0.77g stannous octoate, is dissolved in the 120ml dry toluene.Logical nitrogen, control temperature 60 C reaction 4.5 hours.After reaction finished, suction filtration was removed unreacted stannous acetate, and vacuum-drying obtains the highly reactive polymer of Sn (Oct) end-blocking.
(2) the D-rac-Lactide that the highly reactive polymer that obtains in the step (1) and 7.0g optical purity is 97%ee joins in the polymerizing pipe, fill nitrogen and catch up with oxygen, vacuumize, triplicate, vacuum tightness in the control polymerizing pipe is 75Pa, and 130 ℃ of temperature of reaction were reacted 72 hours, namely obtain the polyoxypropylene of three cladodification-D-poly(lactic acid)-PLLA (PPO-PDLA-PLLA) stereoblock copolymer, its molecular structure is shown in molecular formula among Fig. 3.Products therefrom is purified, and it is 16.2 ten thousand that GPC measures its weight-average molecular weight, and the content that the specific rotatory power method calculates D-LA is 48.7%.Press embodiment 1 listed method, record this polylactic acid stereoscopic segmented copolymer and have very high tacticity, and the mass ratio of three cladodification polyoxypropylenes, PLLA, D-poly(lactic acid) is 1:12:12 in the segmented copolymer; 199 ℃ of fusing points.
Claims (9)
1. method for preparing the polylactic acid stereoscopic segmented copolymer of high molecular is characterized in that concrete steps are:
(1) under anhydrous condition and protection of inert gas, PLLA or PLLA segmented copolymer are dissolved in the organic solvent, add metal carboxylate or metal alkoxide and carry out priming reaction as the polymer end hydroxy activating reagent, obtain the highly reactive polymer of particular functional group's end-blocking;
(2) with above-mentioned highly reactive polymer and dextrorotation rac-Lactide generation ring-opening polymerization, obtain the polylactic acid stereoscopic segmented copolymer of high molecular;
Perhaps be:
(1) under anhydrous condition and protection of inert gas, to gather dextrolactic acid or poly-dextrolactic acid segmented copolymer is dissolved in the organic solvent, add metal carboxylate or metal alkoxide and carry out priming reaction as the polymer end hydroxy activating reagent, obtain the highly reactive polymer of particular functional group's end-blocking;
(2) with above-mentioned highly reactive polymer and levorotatory lactide generation ring-opening polymerization, obtain the polylactic acid stereoscopic segmented copolymer of high molecular.
2. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1, it is characterized in that: described PLLA or PLLA segmented copolymer, perhaps gather dextrolactic acid or poly-dextrolactic acid segmented copolymer, its number-average molecular weight is 3 ~ 100,000.
3. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1 and 2, it is characterized in that: described PLLA and PLLA segmented copolymer, poly-dextrolactic acid and poly-dextrolactic acid segmented copolymer, it is linear polymer, there is and only has a hydroxyl in its polymer molecular chain as end group, and can only be the terminal group of polylactic acid chain segment;
Perhaps described PLLA and PLLA segmented copolymer gather dextrolactic acid and poly-dextrolactic acid segmented copolymer, are star block copolymer.
4. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1, it is characterized in that: described organic solvent is a kind of in toluene, dimethylbenzene, dichlorobenzene, the phenyl ether or wherein multiple, the add-on of described organic solvent is PLLA or PLLA segmented copolymer, perhaps 2 ~ 5 times of poly-dextrolactic acid or poly-dextrolactic acid block copolymerization amount.
5. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1 is characterized in that: described terminal hydroxy group activator metal carboxylate salt or metal alkoxide are a kind of in the inferior tin of stannous octoate, aluminum isopropylate, stannous acetate and lactic acid or wherein multiple.
6. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1, it is characterized in that: described PLLA or PLLA segmented copolymer, perhaps poly-dextrolactic acid or poly-dextrolactic acid segmented copolymer, with the mass ratio of terminal hydroxy group activator be (8 ~ 15): 1.
7. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1, it is characterized in that: the temperature of reaction of described terminal hydroxy group priming reaction is 50 ~ 60
oC, the reaction times is 4 ~ 6 hours.
8. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1 is characterized in that: the consumption mass ratio of described highly reactive polymer and dextrorotation rac-Lactide or levorotatory lactide is (0.5 ~ 1.5): 1.
9. the method for the polylactic acid stereoscopic segmented copolymer of preparation high molecular according to claim 1, it is characterized in that: described ring-opening polymerization is body ring-opening polymerization method, described ring-opening polymerization carries out under oxygen free condition, the vacuum tightness of reaction system is 0.1 ~ 100 Pa, and temperature of reaction is 120 ~ 160
oC, the reaction times is 24 ~ 72 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100205721A CN103073708A (en) | 2013-01-20 | 2013-01-20 | Method for preparing high molecular weight polylactic acid stereoblock copolymer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100205721A CN103073708A (en) | 2013-01-20 | 2013-01-20 | Method for preparing high molecular weight polylactic acid stereoblock copolymer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103073708A true CN103073708A (en) | 2013-05-01 |
Family
ID=48150421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013100205721A Pending CN103073708A (en) | 2013-01-20 | 2013-01-20 | Method for preparing high molecular weight polylactic acid stereoblock copolymer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103073708A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107540824A (en) * | 2017-09-21 | 2018-01-05 | 南京大学 | The method of macromole evocating agent and the condensation open loop solid phase combination synthesis poly- L/D lactic acid of superelevation isotacticity |
| CN111558083A (en) * | 2020-01-14 | 2020-08-21 | 北京四环制药有限公司 | Biodegradable injection filler, preparation method and application thereof |
| CN115427478A (en) * | 2020-09-07 | 2022-12-02 | 株式会社Lg化学 | Polylactic acid stereocomplex and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5270400A (en) * | 1991-12-31 | 1993-12-14 | Maria Spinu | L-Dpolylactide copolymers with controlled morphology |
| JPH10237165A (en) * | 1997-02-20 | 1998-09-08 | Shimadzu Corp | Production of polylactic acid-based copolymer having high molecular weight, and copolymer |
| WO2010038860A1 (en) * | 2008-10-03 | 2010-04-08 | 国立大学法人京都工芸繊維大学 | Polylactic acid composition and method for producing same |
| CN101747501A (en) * | 2008-12-12 | 2010-06-23 | 北京服装学院 | Method for synthesizing high molecular weight polylactic acid |
| WO2012017859A1 (en) * | 2010-08-02 | 2012-02-09 | 学校法人日本大学 | Stereocomplex and method for producing same |
| CN102432852A (en) * | 2011-08-25 | 2012-05-02 | 复旦大学 | Polylactic-acid-based isotactic compound crosslinking copolymer and preparation method thereof |
| CN102746500A (en) * | 2012-07-04 | 2012-10-24 | 北京化工大学 | Method for synthesizing high-molecular-weight poly(lactic acid) through melt polycondensation of lactic acid under catalysis of three-way composite catalyst |
-
2013
- 2013-01-20 CN CN2013100205721A patent/CN103073708A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5270400A (en) * | 1991-12-31 | 1993-12-14 | Maria Spinu | L-Dpolylactide copolymers with controlled morphology |
| JPH10237165A (en) * | 1997-02-20 | 1998-09-08 | Shimadzu Corp | Production of polylactic acid-based copolymer having high molecular weight, and copolymer |
| WO2010038860A1 (en) * | 2008-10-03 | 2010-04-08 | 国立大学法人京都工芸繊維大学 | Polylactic acid composition and method for producing same |
| CN101747501A (en) * | 2008-12-12 | 2010-06-23 | 北京服装学院 | Method for synthesizing high molecular weight polylactic acid |
| WO2012017859A1 (en) * | 2010-08-02 | 2012-02-09 | 学校法人日本大学 | Stereocomplex and method for producing same |
| CN102432852A (en) * | 2011-08-25 | 2012-05-02 | 复旦大学 | Polylactic-acid-based isotactic compound crosslinking copolymer and preparation method thereof |
| CN102746500A (en) * | 2012-07-04 | 2012-10-24 | 北京化工大学 | Method for synthesizing high-molecular-weight poly(lactic acid) through melt polycondensation of lactic acid under catalysis of three-way composite catalyst |
Non-Patent Citations (2)
| Title |
|---|
| MASAYUKI HIRATA ET AL: "Enhanced stereocomplexation by enantiomer adjustment for stereo diblock polylactides with non-equivalent D/L ratios", 《MACROMOLECULAR CHEMISTRY AND PHYSICS》 * |
| MASAYUKI HIRATA ET AL: "Synthesis and Properties of High-Molecular-Weight Stereo Di-Block Polylactides with Nonequivalent D/L Ratios", 《JOURNAL OF POLYMER SCIENCE PART A：POLYMER CHEMISTRY》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107540824A (en) * | 2017-09-21 | 2018-01-05 | 南京大学 | The method of macromole evocating agent and the condensation open loop solid phase combination synthesis poly- L/D lactic acid of superelevation isotacticity |
| CN107540824B (en) * | 2017-09-21 | 2019-07-05 | 南京大学 | Macromole evocating agent and condensation-open loop-solid phase combination synthesis superelevation isotacticity poly- L-/D- lactic acid method |
| CN111558083A (en) * | 2020-01-14 | 2020-08-21 | 北京四环制药有限公司 | Biodegradable injection filler, preparation method and application thereof |
| CN111558083B (en) * | 2020-01-14 | 2021-11-12 | 北京四环制药有限公司 | Biodegradable injection filler, preparation method and application thereof |
| CN115427478A (en) * | 2020-09-07 | 2022-12-02 | 株式会社Lg化学 | Polylactic acid stereocomplex and preparation method thereof |
| CN115427478B (en) * | 2020-09-07 | 2024-02-13 | 株式会社Lg化学 | Polylactic acid stereocomplex and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhu et al. | Catalyst‐Sidearm‐Induced Stereoselectivity Switching in Polymerization of a Racemic Lactone for Stereocomplexed Crystalline Polymer with a Circular Life Cycle | |
| CN108250415B (en) | Poly (gamma-butyrolactone) -b-polylactic acid block copolymer and preparation method thereof | |
| EP3310845B1 (en) | Use of additives to fine-tune the composition of carbonate units in the polymer formed by copolymerization of co2 with epoxide: application to the synthesis of polycarbonate-based block copolymers and of telechelics | |
| Idage et al. | Ring opening polymerization of dilactide using salen complex as catalyst | |
| CN102245673B (en) | Prepare the method for diblock and segmented copolymer | |
| Kan et al. | Facile preparation of stereoblock PLA from ring-opening polymerization of rac-lactide by a synergetic binary catalytic system containing ureas and alkoxides | |
| Masutani et al. | Synthesis and thermomechanical properties of stereo triblock polylactides with nonequivalent block compositions | |
| Hilf et al. | Controlled Synthesis of Multi‐Arm Star Polyether–Polycarbonate Polyols Based on Propylene Oxide and CO2 | |
| Ma et al. | Stereocomplexed three-arm PPO–PDLA–PLLA copolymers: Synthesis via an end-functionalized initiator | |
| Wang et al. | Synthesis of poly (D, L‐lactic acid) modified by cholic acid via direct melt copolycondensation and its characterization | |
| CN105348495A (en) | Catalyst for polylactone preparation | |
| CN103073708A (en) | Method for preparing high molecular weight polylactic acid stereoblock copolymer | |
| CN100497350C (en) | Rare earth complex catalyzing lactide stereo selective polymerization | |
| Adams et al. | (Co) polymerization of (−)-menthide and β-butyrolactone with yttrium-bis (phenolates): tuning material properties of sustainable polyesters | |
| Deng et al. | Polymerization of lactides and lactones. IV. Ring‐opening polymerization of ε‐caprolactone by rare earth phenyl compounds | |
| Bai et al. | Homo‐and random copolymerizations of ω‐pentadecalactone with ε‐caprolactone using isothiourea‐based dual catalysis | |
| KR101318734B1 (en) | Triblock copolymers between polyalkylene carbonate and polylactide and method for producing the same | |
| KR101692988B1 (en) | Polylactide resin having improved thermal stability | |
| Ye et al. | Synthesis of biodegradable material poly (lactic acid‐co‐aspartic acid) via direct melt polycondensation and its characterization | |
| Tang et al. | Crystalline aliphatic polyesters from eight‐membered cyclic (di) esters | |
| Deng et al. | Polymerization of lactides and lactones. II. Ring‐opening polymerization of ε‐caprolactone and dl‐lactide by organoacid rare earth compounds | |
| Feng et al. | Synthesis of Benzoxazine Functionalized Amine‐Bridged Bis (phenolato) Rare Earth Complexes and Their Application in Ring‐Opening Polymerization of rac‐Lactide | |
| CN109337055A (en) | A kind of preparation method of the polylactic acid block polymer of Stereocomplex crystal type | |
| Yan et al. | Facile preparation of long-chain aliphatic polycarbonates containing block copolycarbonates via one-pot sequential organic catalyzed polymerization of macrocyclic carbonates and trimethylene carbonates | |
| Yu et al. | Ring‐opening polymerization of l‐lactide by rare‐earth tris (4‐tert‐butylphenolate) single‐component initiators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130501 |