阅读说明：本技术 一种包含超细立构复合聚乳酸的全生物降解材料 (Full-biodegradable material containing superfine stereo composite polylactic acid ) 是由 吴腾达 杨杰 庄吉彬 刁雪峰 申应军 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种包含超细立构复合聚乳酸的全生物降解材料,原料包括超细立构复合聚乳酸以及生物降解材料：超细立构复合聚乳酸和生物降解材料的重量比为15-35:65-85；其中,所述超细立构复合聚乳酸为：将左旋聚乳酸、右旋聚乳酸混合均匀后,通过密炼机或者双螺杆挤出机在120-180℃混炼4-10分钟得到的立构复合聚乳酸固体,再经过研磨、低温粉碎、过筛得到粉末,其粉末平均粒径Dv(50)小于500um,[Dv(90)-Dv(10)]/2小于400um；所述的超细立构复合聚乳酸与生物降解材料在低于200℃的加工温度下熔融共混,得到所述的包含超细立构复合聚乳酸的全生物降解材料。(The invention discloses a full biodegradable material containing superfine stereo composite polylactic acid, which comprises the following raw materials: the weight ratio of the superfine stereo composite polylactic acid to the biodegradable material is 15-35: 65-85; wherein, the superfine stereo composite polylactic acid is: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, then mixing for 4-10 minutes at 120-180 ℃ by an internal mixer or a double-screw extruder to obtain a stereocomplex polylactic acid solid, and then grinding, crushing at low temperature and sieving to obtain powder, wherein the average particle size Dv (50) of the powder is less than 500um, and [ Dv (90) -Dv (10) ]/2 is less than 400 um; the superfine stereo composite polylactic acid and the biodegradable material are melted and blended at the processing temperature lower than 200 ℃ to obtain the full biodegradable material containing the superfine stereo composite polylactic acid.)

1. A full-biodegradable material containing superfine stereo composite polylactic acid is characterized in that: the raw materials comprise superfine stereo composite polylactic acid and biodegradable materials: the weight ratio of the superfine stereo composite polylactic acid to the biodegradable material is 15-35: 65-85;

wherein, the superfine stereo composite polylactic acid is: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, and then mixing for 4-10 minutes at 120-180 ℃ by an internal mixer or a double-screw extruder to obtain a stereocomplex polylactic acid solid, wherein the mixing ratio of the levorotatory polylactic acid to the dextrorotatory polylactic acid is 4:6-6: 4; grinding, low-temperature pulverizing, and sieving to obtain powder with average particle diameter Dv (50) less than 500um and [ Dv (90) -Dv (10) ]/2 less than 400 um;

the superfine stereo composite polylactic acid and the biodegradable material are melted and blended at the processing temperature of 150-200 ℃ to obtain the fully biodegradable material containing the superfine stereo composite polylactic acid.

2. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the biodegradable material comprises at least one of PBS, PHBV, PPC and PCL.

3. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the mixing temperature of the solid of the stereo composite polylactic acid is 120-180 ℃.

4. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the melting processing temperature of the superfine stereo composite polylactic acid and the biodegradable material is 150-200 ℃.

5. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the blending ratio of the superfine stereo composite polylactic acid/PCL is 18-22:78-82 by weight, the melting temperature is 155-165 ℃, and the injection molding temperature is 160-170 ℃.

6. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the blending ratio of the superfine stereo composite polylactic acid/PCL is 20:80 by weight, the melting temperature is 160 ℃, and the injection molding temperature is 165 ℃.

7. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the blending ratio of the superfine stereo composite polylactic acid/PBS is 13-17:83-87, the melting temperature is 155-165 ℃, and the injection molding temperature is 165-175 ℃.

8. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the blending ratio of the superfine stereo composite polylactic acid/PBS is 15:85 by weight, the melting temperature is 160 ℃, and the injection molding temperature is 170 ℃.

9. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the blending ratio of the superfine stereo composite polylactic acid/PBAT is 33-37:60-70 by weight, the melting temperature is 175-185 ℃, and the injection temperature is 170-180 ℃.

10. The fully biodegradable material comprising ultra-fine stereocomplex polylactic acid according to claim 1, wherein: the weight ratio of the superfine stereo composite polylactic acid/PBAT blend is 35:65, the melting temperature is 180 ℃, and the injection molding temperature is 175 ℃.

Technical Field

The invention relates to a full-biodegradable material containing superfine stereo composite polylactic acid.

Background

The traditional biodegradable material generally has the defects of low temperature resistance and poor strength, and is difficult to realize effective replacement under the existing use condition. Therefore, the scheme for developing the high-performance biodegradable material is suitable for the current mainstream market application requirements, and becomes a problem which is urgently needed to be solved for the popularization and application of the biodegradable material.

Common biodegradable materials have low melting point (50-150 ℃), low crystallinity and low heat distortion temperature. In the daily temperature-resistant (70-90 ℃) application scene, enough temperature-resistant performance guarantee cannot be provided. Because the crystallization capacity of the biodegradable material is weak, the promotion of crystallization through an external process usually makes the processing procedure complicated and the production cost increased, which is not favorable for wide popularization and application. The heat resistance of the biodegradable material is improved by adding the inorganic filler, which is a common material modification method, but the inorganic filler is easy to contain heavy metals and excessive specific elements when in use, so that the compost degradation requirement is not met.

CN201110207647.8 discloses a biodegradable polyethylene film and a preparation method thereof, wherein the biodegradable polyethylene film comprises the following raw materials by weight: 40-55% of high-density polyethylene, 10-30% of polylactic acid stereo complex, 3-25% of epoxy vegetable oil, 15-35% of starch and 3-15% of compatibilizer.

CN201510908115.5 discloses a biodegradable agricultural mulching film. The feed additive is composed of the following substances in parts by weight: 50-60 parts of high-density polyethylene, 30-40 parts of fumaric acid, 5-10 parts of polylactic acid stereocomplex, 3-15 parts of epoxy vegetable oil, 15-35 parts of corn starch, 3-8 parts of compatibilizer, 25-45 parts of starch-based biodegradable material, 0.3-0.8 part of light stabilizer, 0.3-0.5 part of thermal stability, 0.3-0.5 part of thermal oxidative degradation promoter, 0.1-0.3 part of catalyst and 30-40 parts of polyethylene wax. The biodegradable agricultural mulching film provided by the invention has the insecticidal effect of keeping the heat preservation and moisture preservation of the mulching film at the plant growth stage.

CN201711263639.9 discloses a polylactic acid composite material and a preparation method thereof. The polylactic acid composite material and the preparation method thereof comprise the following raw materials in parts by weight: 100 parts of racemic polylactic acid copolymer and 10-40 parts of stereocomplex polylactic acid, wherein in the stereocomplex polylactic acid, 30-70 parts of poly-L-lactic acid and 30-70 parts of poly-D-lactic acid are used. The stereo composite polylactic acid and the racemic polylactic acid are blended, so that the mechanical property of the pure racemic polylactic acid resin is enhanced.

However, none of the above patents relate to the research on the improvement of temperature resistance, and the materials cannot be completely biodegraded by blending and processing polyethylene and stereocomplex polylactic acid.

Disclosure of Invention

The invention mainly aims to provide a full-biodegradable material containing superfine stereo composite polylactic acid.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a full biodegradable material containing superfine stereo composite polylactic acid comprises the following raw materials: the weight ratio of the superfine stereo composite polylactic acid to the biodegradable material is 15-35: 65-85;

wherein, the superfine stereo composite polylactic acid is: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, then mixing for 4-10 minutes at 120-180 ℃ by an internal mixer or a double-screw extruder to obtain a stereocomplex polylactic acid solid, and then grinding, crushing at low temperature and sieving to obtain powder, wherein the mixing ratio of the levorotatory polylactic acid to the dextrorotatory polylactic acid is 4:6-6:4, the average particle size Dv (50) of the powder is less than 500um, and [ Dv (90) -Dv (10) ]/2 is less than 400 um;

wherein Dv (10), Dv (50) and Dv (90) represent the respective particle diameters distributed in the range of 10%, 50% and 90%. [ Dv (90) -Dv (10) ]/2 approximates the half-width of the particle size distribution curve.

The superfine stereo composite polylactic acid and the biodegradable material are melted and blended at the processing temperature of 150-200 ℃ to obtain the fully biodegradable material containing the superfine stereo composite polylactic acid.

The invention defines that the average particle diameter Dv (50) of the stereocomplex polylactic acid powder is less than 500um, and [ Dv (90) -Dv (10) ]/2 is less than 400 um: the stereo composite polylactic acid powder with uniform particle size and proper size is easier to disperse and process, and the overall performance of the material is improved. If Dv (50) is greater than 500um, the impact resistance of the material is more reduced; in the present invention, if [ Dv (90) -Dv (10) ]/2 is more than 400um, both the heat-resistant temperature and the physical properties of the material are lowered; the processing temperature of the melt blending of the superfine stereo composite polylactic acid and the biodegradable material is 150-200 ℃, the stereo composite polylactic acid powder is not melted, the amorphous area part is continuously crystallized at the temperature, and the heat resistance can be maintained; if the processing temperature is higher than 200 ℃, the stereo composite polylactic acid powder is not partially melted to form stereo composite crystals any more, and the improvement of the heat resistance of the blending material is influenced.

In the invention, the biodegradable material comprises at least one of PBS (polybutylene succinate), PBAT (polybutylene terephthalate-adipate), PHA (polyhydroxyalkanoate), PPC (carbon dioxide-propylene oxide copolymer) and PCL (polycaprolactone).

In the preferred embodiment of the invention, the mixing temperature of the solid stereocomplex polylactic acid is 140-170 ℃.

In the preferred embodiment of the invention, the melting processing temperature of the ultra-fine stereo composite polylactic acid and the biodegradable material is 160-180 ℃.

In the preferred embodiment of the invention, the blending ratio of the superfine stereo composite polylactic acid/PCL is 18-22:78-82 by weight, the melting temperature is 155-165 ℃, and the injection temperature is 160-170 ℃.

In the preferred embodiment of the invention, the blending ratio of the superfine stereocomplex polylactic acid/PCL is 20:80 by weight, the melting temperature is 160 ℃, and the injection molding temperature is 165 ℃.

In the preferred embodiment of the invention, the blending ratio of the superfine stereo composite polylactic acid/PBS is 13-17:83-87 by weight, the melting temperature is 155-165 ℃, and the injection temperature is 165-175 ℃.

In the preferred embodiment of the invention, the blending ratio of the superfine stereo composite polylactic acid/PBS is 15:85 by weight, the melting temperature is 160 ℃, and the injection molding temperature is 170 ℃.

In the preferred embodiment of the invention, the weight ratio of the ultra-fine stereo composite polylactic acid/PBAT blend is 33-37:60-70, the melting temperature is 175-185 ℃, and the injection temperature is 170-180 ℃.

In the preferred embodiment of the invention, the weight ratio of the superfine stereo composite polylactic acid/PBAT blend is 35:65, the melting temperature is 180 ℃, and the injection molding temperature is 175 ℃.

The fully biodegradable material containing the stereo composite polylactic acid prepared by the invention has the following advantages:

(1) the superfine stereo composite polylactic acid disclosed by the invention is easy to process and disperse uniformly in a biodegradable material due to small particle size and uniform distribution. Because the prepared stereo composite polylactic acid has a high melting point (220-240 ℃), the material cannot be melted when being processed at the temperature of 150-200 ℃, and meanwhile, the amorphous region of the material can be continuously crystallized, so that the heat resistance of the blended material is promoted to be improved. Compared with the common inorganic filling material, the superfine stereo composite polylactic acid has no problem of excessive heavy metal content, and is safer and more environment-friendly when in use.

(2) The stereo composite polylactic acid material prepared by the invention has high melting point (220-.

(3) Can be repeatedly processed within 150-200 ℃ without influencing the heat resistance of the material.

Detailed Description

Example 1 ultra-fine stereocomplex polylactic acid/PCL blend

Firstly, preparing superfine stereo composite polylactic acid: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, mixing for 7 minutes at 150 ℃ by an internal mixer to obtain a stereocomplex polylactic acid solid, grinding, crushing at low temperature, and sieving to obtain powder, wherein the mixing ratio of the levorotatory polylactic acid to the dextrorotatory polylactic acid is 1:1 by weight.

Grinding, crushing at low temperature, sieving to obtain superfine stereo composite polylactic acid (Dv50 is 400um, [ Dv (90) -Dv (10) ]/2 is 300um) and PCL 6500, mixing uniformly according to the mass ratio of 20:80, melting, blending and extruding at 160 ℃ by a double-screw extruder, granulating, and preparing a sample at 165 ℃ by an injection molding machine.

Example 2 ultra-fine stereocomplex polylactic acid/PBS blend

Firstly, preparing superfine stereo composite polylactic acid: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, mixing for 5 minutes at 160 ℃ by an internal mixer to obtain a stereocomplex polylactic acid solid, grinding, crushing at low temperature, and sieving to obtain powder, wherein the mixing ratio of the levorotatory polylactic acid to the dextrorotatory polylactic acid is 1:1 by weight.

The superfine stereocomplex polylactic acid (Dv50 ═ 200um, [ Dv (90) -Dv (10) ]/2 ═ 320um) and PBS FZ91 are uniformly mixed according to the mass ratio of 15:85, and then the mixture is melted, blended, extruded and granulated by a double-screw extruder at 160 ℃, and then the sample is prepared at 170 ℃ by an injection molding machine.

Example 3 ultra-fine stereocomplex polylactic acid/PBAT blend

Firstly, preparing superfine stereo composite polylactic acid: uniformly mixing the levorotatory polylactic acid and the dextrorotatory polylactic acid, mixing for 5 minutes at 140 ℃ by an internal mixer to obtain a stereocomplex polylactic acid solid, grinding, crushing at low temperature, and sieving to obtain powder, wherein the mixing ratio of the levorotatory polylactic acid to the dextrorotatory polylactic acid is 1:1 by weight.

Uniformly mixing superfine stereocomplex polylactic acid (Dv50 ═ 440um, [ Dv (90) -Dv (10) ]/2 ═ 280um) and PBAT TH801T according to a mass ratio of 35:65, then carrying out melt blending extrusion and granulation by a double-screw extruder at 180 ℃, and then carrying out sample preparation at 175 ℃ by an injection molding machine.

Comparative example 1 common polylactic acid/PCL blend

Uniformly mixing polylactic acid 3001D and PCL 6500 according to the mass ratio of 20:80, then carrying out melt blending extrusion and granulation by a double-screw extruder at 160 ℃, and then preparing a sample by an injection molding machine at 165 ℃.

Comparative example 2 Large-size stereocomplex polylactic acid/PBS blend

Uniformly mixing large-size stereocomplex polylactic acid (Dv 50-1300 um, [ Dv (90) -Dv (10) ]/2-350 um) and PBS FZ91 according to a mass ratio of 15:85, melting, blending, extruding and granulating at 160 ℃ through a double-screw extruder, and preparing a sample at 170 ℃ through an injection molding machine.

Comparative example 3 ultra-fine stereocomplex polylactic acid/PBS was blended at 230 ℃.

Uniformly mixing superfine stereocomplex polylactic acid (Dv50 ═ 400um, [ Dv (90) -Dv (10) ]/2 ═ 300um) and PBS FZ91 according to a mass ratio of 15:85, then carrying out melt blending extrusion and granulation by a double-screw extruder at 230 ℃, and then carrying out sample preparation at 220 ℃ by an injection molding machine.

Comparative example 4 Small-size Large-Dispersion stereocomplex polylactic acid/PBAT blend

Uniformly mixing small-size large-dispersion stereocomplex polylactic acid (Dv 50-460 um, [ Dv (90) -Dv (10) ]/2-600 um) and PBAT TH801T according to a mass ratio of 35:65, then carrying out melt blending extrusion and granulation by a double-screw extruder at 180 ℃, and then carrying out sample preparation at 175 ℃ by an injection molding machine.

TABLE 1

Compared with the comparative example 1, the heat-resistant temperature of the material is obviously improved by blending the superfine stereo composite polylactic acid material and the PCL.

Compared with the example 2, the impact resistance of the material is reduced more by blending the large-size stereo composite polylactic acid and the PBS.

Compared with the example 2, the comparative example 3 is processed at the melting temperature of 230 ℃, the temperature reaches the melting point of the stereocomplex polylactic acid powder, and the stereocomplex crystals formed by cooling and crystallizing after the crystals are melted are less, so that the comparative example 3 does not have higher temperature resistance.

Compared with the example 3, the heat-resistant temperature and the physical property of the material are reduced by blending the small-size large-dispersion stereo composite polylactic acid and the PBAT.

The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims and their equivalents.