CN103265797B - Lactic acid composite material of a kind of high-crystallinity Wholly-degradable and preparation method thereof - Google Patents
Lactic acid composite material of a kind of high-crystallinity Wholly-degradable and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a kind of lactic acid composite material of high-crystallinity Wholly-degradable, that a certain proportion of poly-dextrolactic acid and polyoxyethylene glycol are added in PLLA, by solution blending or melt-mixing method, prepare PLLA/poly-dextrolactic acid/polyoxyethylene glycol matrix material.The Stereocomplex crystal that poly-dextrolactic acid and PLLA are formed in Blending Processes and softening agent polyoxyethylene glycol accelerate the crystallization of PLLA jointly, the poly(lactic acid) sample of high-crystallinity can be obtained in temperature-fall period faster, and each addO-on therapy of matrix material is all biodegradable, namely while this matrix material has high-crystallinity, can biodegradable completely.Its preparation technology is simple, and easy to operate, cost is low.
Description
Technical field
The present invention relates to technical field of polymer materials, be specifically related to lactic acid composite material of a kind of high-crystallinity Wholly-degradable and preparation method thereof.
Background technology
Since entering 21 century, plastics cause pollution and fossil resources problem to become the focus of world wide concern, and the Biodegradable polymer material of the Sustainable development being raw material with biomass and natural resource becomes the research and apply developing direction of jointly attracting attention in the world.
Poly(lactic acid) (PLA) applies maximum kind in current synthesising biological degradable high polymer material, will be widely used in general-purpose plastics field by part replacement polyolefine gradually.Except it is renewable, outside degradable, poly(lactic acid) also has it and has high strength, high strength, moderate barrier properties for gases, high transparent etc., and the fields such as this is all allowed to condition at packaging, medical medicine have larger prospect of the application.But some performances of poly(lactic acid) itself need to improve, and the resistance toheat as poly(lactic acid) is poor, and the heat-drawn wire of the polylactic acid article obtained by injection moulding method only has about 58 DEG C, this greatly limits the range of application of poly(lactic acid).Its thermotolerance is not enough, and the mode by improving polylactic acid crystal degree improves.
The mode of current raising polylactic acid crystal degree has 3 kinds: 1) outer Added Nucleating Agents, as inorganic one-tenth agent: talcum powder, calcium carbonate etc.; Organic nucleating agent: fatty amide etc.; Adding of nucleator can heterogeneous nucleation, significantly improves the crystallization rate of poly(lactic acid); 2) additional plasticizer, as polyoxyethylene glycol (PEG), poly-propyl alcohol, glycerine etc.; Softening agent add the mobility that can improve polylactic acid molecule chain, thus be more prone to enter lattice, improve the crystallization rate of poly(lactic acid); 3) controlled working process, as improved mould temperature, carries out anneal etc.Compare in controlled working process the shaping cost significantly adding material, by the raising polylactic acid crystal speed that adds of adding nucleator or softening agent, there are larger potentiality.But just add nucleator or softening agent at present, it can only improve the crystallization rate of poly(lactic acid) to a certain extent, what often still obtain in temperature-fall period faster is the sample of low-crystallinity.In addition, the biodegradability adding membership infringement poly(lactic acid) of inorganic nucleator.
Summary of the invention
The invention provides a kind of lactic acid composite material of high-crystallinity Wholly-degradable.Lactic acid composite material provided by the invention, can be prepared by the method for solution blending or melt blending, it has higher crystallization rate, can under the rate of temperature fall be exceedingly fast sufficient crystallising, thus obtain the sample with high-crystallinity, respectively form component in addition and all there is biodegradability.
The lactic acid composite material that a kind of high-crystallinity can will be separated completely, described blend is by the PLLA (PLLA) of 69wt% ~ 95wt%, the poly-dextrolactic acid (PDLA) of 0.1wt% ~ 20wt%, and the polyoxyethylene glycol of 1wt% ~ 30wt% (PEG) composition.
Further scheme is: the relative molecular mass of described PLLA is 10,000 ~ 500,000, optical purity is greater than 90%, and the relative molecular mass of poly-dextrolactic acid is 10,000 ~ 500,000, optical purity is greater than 90%.
Further scheme is: the molecular mass of described polyoxyethylene glycol is 100 ~ 20000.
Present invention also offers described high-crystallinity by the preparation method of the lactic acid composite material of solution, to be solution method, to comprise the steps: completely
1) PLLA is configured to 0.1 ~ 10g.dL
-1solution, poly-dextrolactic acid is configured to 0.1 ~ 10g.dL
-1solution, is configured to 0.1 ~ 10g.dL by polyoxyethylene glycol
-1solution;
2) by step 1) in three kinds of solution mix, obtain the mixing solutions of PLLA/poly-dextrolactic acid/polyoxyethylene glycol after uniform stirring;
3) by step 2) in the mixing solutions that obtains volatilize at normal temperatures, except desolventizing; Obtain PLLA/poly-dextrolactic acid/polyoxyethylene glycol matrix material;
4) by step 3) matrix material of the gained solvent that removing is remaining further in vacuum drying oven, time of drying is 4 ~ 48h, drying temperature is 40 ~ 140 DEG C, vacuum tightness is less than 1000Pa.
Present invention also offers another high-crystallinity by the preparation method of the lactic acid composite material of solution, to be melting method, to comprise the steps: completely:
1) utilize melt compounding equipment, by PLLA, poly-right lactic acid and polyoxyethylene glycol mix,
2) step 1) processing temperature that uses is 170-250 DEG C.
Described melt compounding equipment is torque rheometer, forcing machine or Banbury mixer.
The present invention has the following advantages:
(1) matrix material of the present invention has higher crystallization rate, can obtain the sample with high-crystallinity under rate of temperature fall faster.
(2) each component of matrix material of the present invention can both be degradable, i.e. the full degradation material of this matrix material.
(3) preparation method of matrix material of the present invention can be melting method also solution method, and technique is simple, easy handling.
(4) lactic acid composite material of high-crystallinity of the present invention is due to its higher degree of crystallinity, is expected to the modulus significantly improving poly-lactic acid material, the mechanical propertys such as intensity, can improve its thermotolerance and gas barrier property simultaneously.
(5) matrix material of the present invention annealed process can improve and improves its degree of crystallinity further.
Accompanying drawing explanation
Fig. 1 is the embodiment of the present invention and comparative example melting process figure;
Fig. 2 is comparative example 1 and the embodiment 2 melting curve figure by 10 DEG C/min temperature rise rate after the rate of temperature fall of 40 DEG C/min.
Embodiment
Embodiment 1 ~ 5 and comparative example 1 ~ 3 obtain for adopting solution method, and embodiment 6 obtains for adopting melting method.
Embodiment 1
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 0.1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use; 0.5g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) poly-dextrolactic acid dichloromethane solution step (1) prepared and polyoxyethylene glycol dichloromethane solution all add in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/1/5)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Embodiment 2
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 0.1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use; 1g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) poly-dextrolactic acid dichloromethane solution step (1) prepared and polyoxyethylene glycol dichloromethane solution all add in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/1/10)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Embodiment 3
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 0.1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use; 2g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) poly-dextrolactic acid dichloromethane solution step (1) prepared and polyoxyethylene glycol dichloromethane solution all add in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/1/20)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Embodiment 4
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use; 1g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) poly-dextrolactic acid dichloromethane solution step (1) prepared and polyoxyethylene glycol dichloromethane solution all add in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/10/10)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Embodiment 5
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 0.1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use; 1g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) poly-dextrolactic acid dichloromethane solution step (1) prepared and polyoxyethylene glycol dichloromethane solution all add in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/1/20)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Embodiment 6
(1) 35.6g is gathered Poly-L-lactic acid, 4g polyoxyethylene glycol, 0.4g gathers dextrorotation poly(lactic acid) and carries out blended in torque rheometer, and blending temperature is 180 DEG C, and rotating speed is 40r/min, and the blended time is 5min.
(2) by the product that step (2) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (89/1/10)/poly-dextrolactic acid/polyoxyethylene glycol composite sample.
Comparative example 1
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use;
(2) solution step (1) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(3) by the product that step (2) obtains, vacuum-drying 48h at 50 DEG C, obtains pure PLLA sample.
Comparative example 2
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 1g polyoxyethylene glycol is added in 10ml dichloromethane solution, stir 3h; Stand for standby use;
(2) the polyoxyethylene glycol dichloromethane solution that step (1) prepares all is added in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, obtains PLLA/polyoxyethylene glycol composite sample that ratio is (100/10).
Comparative example 3
(1) at room temperature 10g PLLA is added in 100ml dichloromethane solution, stir 3h; Stand for standby use; 0.1g being gathered dextrolactic acid adds in 10ml dichloromethane solution, stirs 3h; Stand for standby use;
(2) the poly-dextrolactic acid dichloromethane solution that step (1) prepares all is added in PLLA dichloromethane solution, stir 3h;
(3) solution step (2) prepared at room temperature leaves standstill 48h, and volatilization is except desolventizing;
(4) by the product that step (3) obtains, vacuum-drying 48h at 50 DEG C, the PLLA that the ratio that obtains is (100/1)/poly-dextrolactic acid composite sample.
Gained embodiment and comparative example, record its melting process with the temperature rise rate to 190 of 10 DEG C/min DEG C again after cooling to 40 DEG C by the rate of temperature fall of 10 DEG C/min after melting 5min after adopting DSC to rise to 190 DEG C with the temperature rise rate of 100 DEG C/min, its melting process correlated results is shown in Fig. 1 and table 1.Investigate comparative example 1 in addition and embodiment 2 the results are shown in Figure 2 and table 1 by the melting curve of 10 DEG C/min temperature rise rate after the rate of temperature fall of 40 DEG C/min.
By the parameter of DSC melting curve gained in table 1. embodiment 1 ~ 5 and comparative example 1 ~ 3
Note: embodiment 21 and comparative example 1-1 are the samples after the rate of temperature fall of embodiment 2 and comparative example 140 DEG C/min, Tcc is cold crystallization peak temperature, and Tm is melting peak temperature, and Δ Hcc is cold crystallization heat content, Δ Hm is melting enthalpy, Xc be homopolymer crystal structure degree its calculated by formula 1 and obtain;
Formula 1:X
c=(Δ H
m-Δ H
cc)/(1-2W
pDLA%-W
pEG%)/Δ H
0× 100%
From Fig. 1 and table 1, PLLA of the present invention/poly-dextrolactic acid/polyoxyethylene glycol matrix material, cold crystallization peak in its melting process all disappears (embodiment 2,3,4,5,6), show matrix material of the present invention crystallization completely in temperature-fall period, and for pure sample (comparative example 1), all there is a larger cold crystallization peak in PLLA/polyoxyethylene glycol matrix material (comparative example 2) and PLLA/poly-dextrolactic acid matrix material (comparative example 3).Show that matrix material of the present invention has higher crystallization rate, to such an extent as to can crystallization completely in temperature-fall period.Can see from table 1 that the degree of crystallinity of PLLA of the present invention/poly-dextrolactic acid/polyoxyethylene glycol matrix material (embodiment 2,3,4,5,6) compares to pure sample (comparative example 1), PLLA/polyoxyethylene glycol matrix material (comparative example 2) and PLLA/poly-dextrolactic acid matrix material (comparative example 3) have and significantly improve simultaneously.Especially, the degree of crystallinity of embodiment 2,3,4,6 has all exceeded 30%, namely matrix material of the present invention has one and is provided with a higher degree of crystallinity faster while crystallization velocity, for a kind of high-crystallinity can the Wholly-degradable lactic acid composite material of rapid crystallization.
From Fig. 2 and table 1, PLLA of the present invention/poly-dextrolactic acid/polyoxyethylene glycol matrix material still can crystallization completely under rate of temperature fall (40 DEG C/min) faster, and do not show cold crystallization peak (embodiment 2), its degree of crystallinity corresponding also reaches 34.4%, is still in a higher level; And pure PLLA (comparative example 1) is almost uncrystallizable at the rate of temperature fall of 40 DEG C/min.Show that PLLA of the present invention/poly-dextrolactic acid/polyoxyethylene glycol matrix material has crystallization rate faster thus, even if the sample of high-crystallinity still can be formed in temperature-fall period faster.Processing space is a non-isothermal process, in conventional processes, PLLA of the present invention/poly-dextrolactic acid/polyoxyethylene glycol matrix material is hopeful to complete crystallization thus, form the sample of high-crystallinity, thus the mechanical property, thermotolerance, gas barrier property etc. of poly(lactic acid) can be improved.
Claims (1)
1. a preparation method for the lactic acid composite material of high-crystallinity Wholly-degradable, is characterized in that:
Described blend by the PLLA (PLLA) of 69wt% ~ 95wt%, the poly-dextrolactic acid (PDLA) of 0.1wt% ~ 20wt%, and the polyoxyethylene glycol of 1wt% ~ 30wt% (PEG) composition; The relative molecular mass of described PLLA is 10,000 ~ 500,000, optical purity is greater than 90%, and the relative molecular mass of poly-dextrolactic acid is 10,000 ~ 500,000, optical purity is greater than 90%; The molecular mass of described polyoxyethylene glycol is 100 ~ 20000;
The lactic acid composite material of described high-crystallinity Wholly-degradable is prepared by the following method:
1) PLLA is configured to 0.1 ~ 10 g.dL
-1solution, poly-dextrolactic acid is configured to 0.1 ~ 10 g.dL
-1solution, is configured to 0.1 ~ 10 g.dL by polyoxyethylene glycol
-1solution;
2) kind of the solution of three in step 1) is mixed, after uniform stirring, obtain the mixing solutions of PLLA/poly-dextrolactic acid/polyoxyethylene glycol;
3) by step 2) in the mixing solutions that obtains volatilize at normal temperatures, except desolventizing; Obtain PLLA/poly-dextrolactic acid/polyoxyethylene glycol matrix material;
4) by the matrix material of the step 3) gained solvent that further removing is remaining in vacuum drying oven, time of drying is 4 ~ 48h, drying temperature is 40 ~ 140 DEG C, vacuum tightness is less than 1000Pa.
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| CN104592727B (en) * | 2015-01-19 | 2016-08-24 | 浙江大学 | Can the biodegradable physics hydrogel and preparation method thereof of in situ quick-gelatinizing |
| CN104788921B (en) * | 2015-04-07 | 2018-03-16 | 四川大学 | Stereocomplex type PLA transparent article with high-crystallinity and preparation method thereof |
| CN107970493B (en) * | 2016-10-25 | 2021-08-17 | 先健科技(深圳)有限公司 | Absorbable plugging device |
| CN107325302A (en) * | 2017-07-13 | 2017-11-07 | 东华大学 | A kind of preparation method of polylactic acid stereoscopic composite |
| CN108219208A (en) * | 2017-12-05 | 2018-06-29 | 湖北光合生物科技有限公司 | A kind of thermoplastic starch powder composite material and preparation method thereof |
| CN109912945B (en) * | 2018-11-19 | 2021-04-30 | 江苏科技大学 | High-molecular-weight polylactic acid material and preparation method thereof |
| CN110564124B (en) * | 2019-10-29 | 2021-08-17 | 重庆理工大学 | Composite material for improving compatibility and crystallinity of PLLA/PMMA and preparation method thereof |
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