CN1328304C - Method for preparing copolymers lactic acid/rubber - Google Patents
Method for preparing copolymers lactic acid/rubber Download PDFInfo
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- CN1328304C CN1328304C CNB2005100305462A CN200510030546A CN1328304C CN 1328304 C CN1328304 C CN 1328304C CN B2005100305462 A CNB2005100305462 A CN B2005100305462A CN 200510030546 A CN200510030546 A CN 200510030546A CN 1328304 C CN1328304 C CN 1328304C
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Abstract
The present invention relates to a method for preparing lactic acid/rubber copolymers. The present invention uses a copolymerization method to make lactic acid into end hydroxy polylactic acid having the molecular weight of 1000 to 60000 after dehydration, condensation polymerization and end group modification without the need of directly preparing pure lactide and PLA having a high molecular weight, and then copolymerization and chain extension action are carried out between the end hydroxy polylactic acid and end isocyanate group rubber having the molecular weight of 400 to 10000 in order to prepare lactic acid/rubber copolymers. The technology of the method is simple and easy to control, and production cost is low. The types and the dose of the copolymers and the operating conditions of a copolymerization process can be reasonably selected during implement in order to conveniently control the components and the structures of the copolymers, and the dynamic, mechanical and biodegradable performances, etc. of the copolymers can be controlled. The method for preparing lactic acid/rubber copolymers has the characteristic of molecular design. Therefore, the lactic acid/rubber copolymers prepared by the present invention have favorable post-processing performance and wide application.
Description
Technical field
The present invention relates to the preparation method of polymkeric substance, especially relate to the preparation of lactic acid copolymer.
Background technology
Lactic acid polymer claims poly(lactic acid) (Poly (lactic acid) again; Be called for short: PLA), its main production raw material is to be made by amylofermentation.Poly(lactic acid) and post-treatment product thereof have favorable biological degradability and recyclability, meet the human environment protection and the strategy of sustainable development, and therefore very fine application prospect is arranged.But pure poly(lactic acid) is a kind of hard brittle material, and this character has had a strong impact on its workability and range of application.In order to enlarge its Application Areas, many investigators explore polylactic acid modified, and main methods of modification has at present:
(1) modification by copolymerization method
Modification by copolymerization be intended to poly(lactic acid) main chain in introduce another kind of molecule segment, be used for reducing the regularity and the degree of crystallinity of polylactic acid chain segment, thereby improve the elasticity and the snappiness of poly(lactic acid).Introduce polyoxyethylene glycol hydroaropic substances such as (PEG) in oil loving polylactic acid chain segment, it is amphipathic that this multipolymer is had, and this character makes it at pharmaceutical sanitary field purposes [Metters A.Polymer.2000,41:3993 widely be arranged; Metters A.J.Phys.Chem.B., 2000,104:7043; Mason M N.Macromolecules, 2001,34:4630; Metters A.AIChE Journal, 2001.47 (6): 1432].Also can introduce caprolactone (CL) [Teng C Q, et al.J Polym Sci.A., 2004,42:5045.], [Tan (a state in the Zhou Dynasty) will is clear for glycollide (GA), Shen Xinyuan .CN119559A.] etc. biodegradable segment improve the degradation property of poly(lactic acid), can also be by introducing polymethylmethacrylate (PMMA) [[7] Shinoda H.Macromolecules.2001,34:6243.], polyimide (PI) [Schmidt S C.Macromolecules, 1999,32:4794.] etc. non-biodegradation material and obtain some special mechanical properties or functional.
(2) blending modification method
The blend with it of research at present biodegradable has polycaprolactone, poly butyric ester (PHB) [Liu X.J Environmental Polymer Degradation, 1997,5:225.Ohkoshi I.Abe H.Polymer, 2000,41:5985.], polyester fat acid anhydride [DavisM C.et al.Macromolecules, 1996,29:2205.], thermoplastic starch [USP6211325.] etc., nonbiodegradable have urethane, a poly-isoamyl glycol grafting vinyl acetate rubber [Jin H, Chin I.J.European Polymer, 2000,36:165; Hiki S, et al Polymer, 2000,41:7369.] etc.Blending and modifying technology is simple, easy handling, and cost is low, is beneficial to popularization, has become a new trend of polylactic acid modified research at present.
(3) composite modified method
With the poly(lactic acid) is the compound fragility that can improve poly(lactic acid) of matrix and other materials, different shape such as that lactic acid composite material can be processed into is tabular, bar-shaped, screw.The lactic acid composite material forming method has these several: 1), and with polylactic acid melt and blending in of fibers, then with mixture rapid cooling forming in mould.2), with the powder and the blending in of fibers of porphyrize, then at certain pressure and temperature compacted under.3), poly(lactic acid) is dissolved in the solvent, adds fiber and interfacial compatibilizer again, mix then, remove the back of desolvating at certain temperature and pressure compacted under.Present is widely used, and can be used as bone fracture internal fixing device as charcoal fiber reinforcement lactic acid composite material.
Poly-glycollide (PGA) fiber reinforcement lactic acid composite material can be used as operating sutures [Majola A, et al.Clinic Orthopedy, 1991, (286): 260.].The Spare tire cover that the poly(lactic acid) of the common exploitation of the beautiful and Toyota in east and natural kenaf matrix material are used for automobile wait for bus interior material [Japan Chem.Week, 2004; 45 (2258): 7.].
Summary of the invention
The object of the present invention is to provide that a kind of production cost is low, the preparation method of the lactic acid copolymer (hereinafter to be referred as the PLA multipolymer) of easy easy control on the technology, the lactic acid copolymer of taking this method to make has that molecular weight height, biological degradability are good, the post-treatment excellent property, advantage such as have wide range of applications.
A kind of preparation method of copolymers lactic acid/rubber of the present invention adopts the technique means of copolymerization and chain extension simultaneously, earlier lactic acid polymer is made in the acid by dehydrating lactic polycondensation, by the acting in conjunction of copolymerization and chain extension, prepares copolymers lactic acid/rubber then.Easy to be easy to control on this preparation method's technology, production cost is low.In the specific implementation, reasonably selective reaction raw material, consumption and operational condition are controlled the multipolymer The Nomenclature Composition and Structure of Complexes more easily, thereby control mechanics, mechanical property and the biodegradability of multipolymer, have the feature of molecular designing.Therefore, with the post-treatment excellent property of the lactic acid copolymer of the inventive method preparation, range of application is very extensive.
It is 1 that the present invention adopts the melt polycondensation legal system to be equipped with molecular weight earlier, 000～60,000 hydroxyl-terminated polylactic acid, the hydroxyl-terminated polylactic acid that reaction is obtained is dissolved in the organic solvent again, be 100～10 with molecular weight then, the isocyanate terminated basic rubber of other of 000 carries out copolyreaction, forms multipolymer, thereby obtains copolymers lactic acid/rubber.
Reaction formula is as follows:
(1) hydroxyl-terminated polylactic acid is synthetic
HO-PLA-COOH+HO-M-OH→HO-PLA-COO-M-OH+H
2O (1)
(2) isocyanate terminated basic rubber is synthetic
HO-R-OH+OCN-I-NCO→OCN-I-NHOCO-R-OCONH-I-NCO (2)
(3) copolyreaction
For for simplicity, HO-PLA-COO-M-OH is designated as in the equation (1): HO-PLA-OH,
OCN-I-NHOCO-R-OCONH-I-NCO is designated as in the equation (2): OCN-R-NCOHO-PLA-OH+OCN-R-NCO → O-PLA-OCONH-R-NHOC
n(3)
O-PLA-OCONH-R-NHOc in the equation (3)
nBe designated as: PLA-R
nWherein: PLA represents poly(lactic acid);
HO-PLA-OH represents hydroxyl-terminated polylactic acid;
HO-M-OH represents terminal hydroxy group properties-correcting agent;
HO-R-OH represents terminal hydroxy group rubber:
OCN-I-NCO represents vulcabond;
OCN-R-NCO represents isocyanate terminated basic rubber:
PLA-R
nThe expression copolymers lactic acid/rubber.
The preparation method of copolymers lactic acid/rubber of the present invention is as follows;
With hydroxyl-terminated polylactic acid and one or more other isocyanate terminated basic rubber, in organic solvent, under 50～100 ℃, condition of normal pressure, carry out copolyreaction and obtained the lactic acid copolymerization in 1.0～3.0 hours.The viscosity-average molecular weight of described hydroxyl-terminated polylactic acid is 1,000～60,000, and the viscosity-average molecular weight of described other isocyanate terminated basic rubber is 400～10,000.Wherein, isocyanate terminated basic rubber weight be hydroxyl-terminated polylactic acid and one or more other isocyanate terminated basic rubber gross weight 10～70%.
Above-mentioned hydroxyl-terminated polylactic acid can adopt following method synthetic:
Lactic raw material and terminal hydroxy group properties-correcting agent dewater under certain temperature and vacuum condition, then at higher temperature, more to a certain degree polyreaction takes place under the effect of low pressure and catalyzer, promptly obtain water white transparency solid state hydroxyl-terminated polylactic acid after the room temperature cooling, its molecular weight is about 1,000～60,000.
Specifically lactic acid and the terminal hydroxy group properties-correcting agent with the L type is raw material, dewaters 2～20 hours under 100～140 ℃ and 80～150Pa negative pressure; Keep temperature of reaction then at 100～140 ℃, pressure is reduced to 20～100Pa, adds catalyzer, continues reaction 3～5 hours; At last, temperature rises to 150～200 ℃, and pressure is reduced to 3～160Pa, continues reaction 4～24 hours, promptly gets hydroxyl-terminated polylactic acid; Described lactic acid is recommended as the lactic acid of L type weight content 〉=97%, and the weight ratio of described lactic acid, terminal hydroxy group properties-correcting agent and catalyzer is 1: 0.005～0.05: 0.001～0.05.Employed catalyzer comprises but is not limited to: stannous octoate, tin protochloride, tin tetrachloride or antimonous oxide etc.
Above-mentioned isocyanate terminated basic rubber can adopt following solution polymerization process method to obtain.
Rubber is dissolved in the organic solvent solvent, adds vulcabond again, under 30～100 ℃ and normal pressure, reacted 1～4 hour, obtain isocyanate terminated basic rubber.Wherein, the rubber of stating and the weight ratio of vulcabond are 1: 0.03～0.3.
Described rubber is that hydroxyl value is that 0.05～5.00mmol/g, molecular weight are 100～10,000 rubber, molecular weight is especially with 400～10, and 000 is advisable, and includes but not limited to hydroxy'terminated butadiene nitrile rubber (HTBN), hydroxyl terminated polybutadiene rubber (HTPB) or end hydroxy styrene-butadiene rubber (HTBS) etc.
Vulcabond I includes but not limited to: tolylene diisocyanate (TDI), 4,4 '-diphenylmethanediisocyanate (MDI), hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), trimethyl hexamethylene diisocyanate (TMDI), dimer acid diisocyanate (DDI) or lysinediisocyanate (LDI) etc.
Terminal hydroxy group properties-correcting agent M includes but not limited to: polyester diol or polyether Glycols etc.
Method of the present invention does not need directly to prepare high-molecular weight PLA and pure rac-Lactide, and only need prepare terminal hydroxy group PLA polymkeric substance by the acid by dehydrating lactic polycondensation, pass through then and the rubber copolymerized preparation copolymers lactic acid/rubber of isocyanate terminated base, this technology is easy to be easy to control, production cost is low, is easy to commercialization and promotes.The present invention adopts the method for copolymerization and chain extension simultaneously, by molecular designing control multipolymer The Nomenclature Composition and Structure of Complexes, thereby control mechanics, mechanical property and the biodegradability of multipolymer easily, the copolymers lactic acid/rubber that obtains can be used as the preparation film, feature with molecular designing also can be as the compatilizer of lactic acid/rubber co-mixing system.Therefore, with the post-treatment excellent property of the lactic acid copolymer of the inventive method preparation, range of application is very extensive.
Description of drawings
Fig. 1 is poly(lactic acid) (PLA) and polybutadiene rubber (PB) copolymer film atomic force microscope photo,
Fig. 2 is poly(lactic acid) (PLA) and paracril (BN) multipolymer atomic force microscope photo.
Embodiment:
To help to understand the present invention by following examples, but not limit content of the present invention.
Embodiment 1 preparation poly(lactic acid)/polybutadiene rubber (PLA/PB) multipolymer
1.1 preparation hydroxyl-terminated polylactic acid
In the 500ml three-necked flask, add 300g L-lactic acid (LLA) and 4.41g polyoxyethylene glycol (PEG400), be heated with stirring to 100 ℃, 100Pa vacuum under pressure dehydration 12h.Add the 1.5g antimonous oxide then and make catalyzer, stir, keep 130 ℃, continue reaction 4h.Be warming up to 160 ℃ at last again, reaction 20h.Whole process is all carried out under reduced pressure atmosphere, and pressure of the inside of a bottle is: reaction 100Pa in early stage, reaction 75Pa in mid-term, reaction later stage 20Pa.
After reaction finished, product was poured out, and the room temperature cooling gets the water white transparency solid.By infrared spectra and nuclear magnetic resonance spectroscopy, confirm as poly(lactic acid).Recording its weight-average molecular weight with Ubbelohde viscometer is 26536.
1.2 prepare isocyanate terminated basic polybutadiene rubber
Its method is to be 0.93mmol/g with quantitative hydroxyl value, and number-average molecular weight is that 2300～2800 hydroxyl terminated polybutadiene rubber is dissolved in the trichloromethane, joins in the 500ml three-necked flask, adds quantitative HDI then.The system for the treatment of stirs, and beginning slowly is warming up to 75～80 ℃, and reaction 3h promptly obtains isocyanate terminated basic polybutadiene rubber under this temperature.
1.3 preparation PLA/PB multipolymer
1.1 prepared poly(lactic acid) are dissolved in the trichloromethane, add in proportion in the isocyanate terminated basic polybutadiene rubber of 1.2 preparations, the PLA/PB mass ratio is (as shown in Table 1) between 20/80～80/20, stir simultaneously, under 75 ℃, condition of normal pressure, react 3h, pour out product, treat promptly to get the PLA/PB multipolymer after the solvent evaporates.This copolymer film atomic force microscope photo is seen Fig. 1.
Table one: the physical properties of different feed ratio PLA/PB multipolymers
Embodiment 2 preparation poly(lactic acid)/paracril (PLA/BN) multipolymers
2.1 preparation hydroxyl-terminated polylactic acid
With 1.1 preparation method among the embodiment 1.
2.2 prepare isocyanate terminated basic paracril
Its method is to be 0.45mmol/g with quantitative hydroxyl value, and number-average molecular weight is that 2700 hydroxy'terminated butadiene nitrile rubber is dissolved in the trichloromethane, joins in the 500ml three-necked flask, adds quantitative HDI then.The system for the treatment of stirs, and beginning slowly is warming up to 75～80 ℃, and reaction 3h promptly obtains isocyanate terminated basic paracril under this temperature.
2.3 preparation PLA/BN multipolymer
2.1 prepared poly(lactic acid) are dissolved in the trichloromethane, pressing different ratios adds in the 2.2 isocyanate terminated basic paracrils that prepare, the PLA/BN mass ratio is between 20/80～80/20, stir simultaneously, under 75 ℃, condition of normal pressure, react 3h, pour out product, treat promptly to get the PLA/BN multipolymer after the solvent evaporates.This copolymer film atomic force microscope photo as shown in Figure 2.
Embodiment 3 preparation poly(lactic acid)/polybutadiene rubber (PLA/BS) multipolymers
3.1 preparation hydroxyl-terminated polylactic acid
With 1.1 preparation method among the embodiment 1.
3.2 prepare isocyanate terminated basic styrene-butadiene rubber(SBR)
Its method is to be 0.6mmol/g with quantitative hydroxyl value, and number-average molecular weight is that 2500 end hydroxy styrene-butadiene rubber is dissolved in the trichloromethane, joins in the 500ml three-necked flask, adds quantitative HDI then.The system for the treatment of stirs, and beginning slowly is warming up to 75～80 ℃, and reaction 3h promptly obtains isocyanate terminated basic styrene-butadiene rubber(SBR) under this temperature.
3.3 preparation PLA/BS multipolymer
3.1 prepared poly(lactic acid) are dissolved in the trichloromethane, pressing different ratios adds in the 3.2 isocyanate terminated basic styrene-butadiene rubber(SBR) that prepare, the PLA/BS mass ratio is between 20/80～80/20, stir simultaneously, under 75 ℃, condition of normal pressure, react 3h, pour out product, treat promptly to get the PLA/BS multipolymer after the solvent evaporates.
Claims (9)
1. the preparation method of a copolymers lactic acid/rubber, it is characterized in that: in organic solvent, under 50～100 ℃ and the condition of normal pressure, with viscosity-average molecular weight is 1,000～60,000 hydroxyl-terminated polylactic acid and another or several viscosity-average molecular weight are 400～10,000 isocyanate terminated basic rubber carried out copolyreaction 1.0～3.0 hours, promptly got copolymers lactic acid/rubber; Wherein the gross weight of isocyanate terminated basic rubber accounts for 10～70% of hydroxyl-terminated polylactic acid and isocyanate terminated basic rubber weight sum.
2. the preparation method of copolymers lactic acid/rubber as claimed in claim 1, it is characterized in that: described hydroxyl-terminated polylactic acid is to adopt following method to make: with the lactic acid and the terminal hydroxy group properties-correcting agent of L type weight content 〉=97% is raw material, dewaters 2～20 hours under 100～140 ℃ and 80～150Pa negative pressure; Keep temperature of reaction then at 100～140 ℃, pressure is reduced to 20～100Pa, adds a kind of as catalyzer in stannous octoate, tin protochloride, tin tetrachloride or the antimonous oxide, continues reaction 3～5 hours; At last, temperature rises to 150～200 ℃, and pressure is reduced to 3～160Pa, continues reaction 4～24 hours, promptly gets hydroxyl-terminated polylactic acid; The weight ratio of described lactic acid, terminal hydroxy group properties-correcting agent and catalyzer is 1: 0.005～0.05: 0.001～0.05; Described terminal hydroxy group properties-correcting agent is one or more in polyester diol, the polyether Glycols.
3. press the preparation method of the described copolymers lactic acid/rubber of claim 2, it is characterized in that: described isocyanate terminated basic rubber is to adopt following solution polymerization process to make: in organic solvent, under 30～100 ℃ and the normal pressure, hydroxyl value is that 0.05～5.00mmol/g, molecular weight are 100～10,000 rubber and di-isocyanate reaction 1～4 hour obtain isocyanate terminated basic rubber; The weight ratio of described rubber and vulcabond is 1: 0.03～0.3; Described rubber is hydroxy'terminated butadiene nitrile rubber, hydroxyl terminated polybutadiene rubber or end hydroxy styrene-butadiene rubber.
4. by the preparation method of claim 1 and 3 described copolymers lactic acid/rubbers, it is characterized in that: described organic solvent is one or more in trichloromethane, tetrahydrofuran (THF), toluene, dimethylbenzene, acetone, vinyl acetic monomer, N-BUTYL ACETATE, methylethylketone, dimethyl formamide, mibk, the ethylene glycol ether acetate.
5. by the preparation method of the described copolymers lactic acid/rubber of claim 2, it is characterized in that: in the preparation process of described hydroxyl-terminated polylactic acid, the weight ratio of described catalyzer and lactic raw material is 0.1～1.0%; In the described final step reaction, temperature is 160～180 ℃.
6. by the preparation method of the described copolymers lactic acid/rubber of claim 3, it is characterized in that: described rubber is one or more in hydroxy'terminated butadiene nitrile rubber, hydroxyl terminated polybutadiene rubber or the end hydroxy styrene-butadiene rubber.
7. by the preparation method of the described copolymers lactic acid/rubber of claim 4, it is characterized in that: described terminal hydroxy group properties-correcting agent is that number-average molecular weight is 400 polyoxyethylene glycol.
8. by the preparation method of the described copolymers lactic acid/rubber of claim 5, it is characterized in that: described organic solvent is an ammonia ester level trichloromethane.
9. press the preparation method of the described copolymers lactic acid/rubber of claim 3, it is characterized in that: described vulcabond is a tolylene diisocyanate, 4, one or more in 4 '-diphenylmethanediisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, trimethyl hexamethylene diisocyanate, dimer acid diisocyanate or the lysinediisocyanate.
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| CN103003360B (en) * | 2010-06-15 | 2014-12-10 | 巴斯夫欧洲公司 | Method for producing blends from polylactides (PLA) and thermoplastic polyurethanes (TPU) |
| CN105440609B (en) * | 2015-04-16 | 2017-04-19 | 湖南工业大学 | High-toughness polylactic acid based material and preparation process therefor |
| CN109181067B (en) * | 2018-08-22 | 2021-06-08 | 四川之江高新材料股份有限公司 | Preparation method of graphene fluoride-containing polyethylene mixture for 3D printing |
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| CN1594392A (en) * | 2004-07-15 | 2005-03-16 | 合肥工业大学 | Method for preparing film poly-L-lactic acid copolymer by inner plasticizing |
| JP2005187528A (en) * | 2003-12-24 | 2005-07-14 | Nippon Polyurethane Ind Co Ltd | Powder polyurethane resin for flash molding, and method for producing the same and method for flash molding |
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| JP2005187528A (en) * | 2003-12-24 | 2005-07-14 | Nippon Polyurethane Ind Co Ltd | Powder polyurethane resin for flash molding, and method for producing the same and method for flash molding |
| CN1594392A (en) * | 2004-07-15 | 2005-03-16 | 合肥工业大学 | Method for preparing film poly-L-lactic acid copolymer by inner plasticizing |
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