A translucent heat-resistant polylactic acid composite material and its preparation method

Abstract

The invention relates to a translucent heat-resistant polylactic acid composite material and a preparation method thereof. The material consists of the following components in parts by mass: 100 parts of polylactic acid (PLA), 1 to 5 parts of nucleating agent A, 2~8 parts of nucleating agent B, 2~6 parts of auxiliary nucleating agent, 0.2~3 parts of catalyst, 2~5 parts of polyvinylpyrrolidone, part of polylactic acid resin and nucleating agent, auxiliary nucleating agent, catalyst, polyvinylpyrrolidone The alkanone is uniformly mixed through a high-speed mixer, extruded through a twin-screw extruder to obtain a nucleating masterbatch, and then the masterbatch is mixed with the remaining PLA high-speed mixer evenly, and then extruded and granulated to obtain the present invention. Translucent heat-resistant polylactic acid composite material, the polylactic acid of the present invention has excellent light transmittance and good haze, overcomes the shortcomings of traditional heat-resistant crystalline polylactic acid with low thermal deformation temperature, long molding cycle, and poor transparency .

Description

technical field [0001] The invention belongs to the field of degradable plastics, in particular to a translucent heat-resistant polylactic acid composite material and a preparation method thereof. Background technique [0002] Polylactic acid (PLA) is a polymer material synthesized by polymerization of lactic acid or lactide. Both lactic acid and lactide can be fermented with starch-rich natural crops such as corn and cassava. Response gets. Therefore, polylactic acid is considered as a bio-based material and also a degradable plastic with excellent performance. [0003] After high-speed cooling of the polylactic acid (PLA) melt, a transparent amorphous polylactic acid (PLA) can be obtained. This polylactic acid (PLA) has no heat resistance, and its thermal deformation temperature is only 55~60°C. It is used in the field of hot water contact and cannot even meet the needs of conventional transportation. Especially for polylactic acid (PLA) materials for manufacturing dispo...

AI Technical Summary

Problems solved by technology

[0003] After high-speed cooling of the polylactic acid (PLA) melt, a transparent amorphous polylactic acid (PLA) can be obtained. This polylactic acid (PLA) has no heat resistance, and its thermal deformation temperature is only 55~60°C. It is used in the field of hot water contact and cannot even meet the needs of conventional transportation. Especially for polylactic acid (PLA) materials for manufacturing disposable consumer goods such as aircraft aviation cups, the transparency, heat resistance and biodegradability of the material must be considered at the same time

In terms of improving the heat resistance of polylactic acid, there are mainly two methods: increasing the crystallinity and increasing the glass transition temperature. However, as the crystallinity of polylactic acid increases, polylactic acid will form some large spherulites. When the size of these spherulites exceeds A certain range will seriously affect the light transmittance

Increasing the glass transition temperature of polylactic acid is also a good way to improve heat resistance, but usually requires adding a large amount of high glass transition temperature resins (such as polymethyl methacrylate and other non-degradable resins) or inorganic fillers, a large amount of inorganic fillers Filling will seriously affect the transparency of polylactic acid

[0004] The patent with the publication number CN103467947A discloses a polylactic acid composite material with talcum powder as a filler and a nucleating agent and a preparation method thereof, but the polylactic acid prepared in this way has poor toughness due to the addition of a large amount of talc powder. And the product cannot be transparent

[0005] The patent with the publication number CN106543664A discloses a method of adding a large amount of non-degradable transparent resin and cooperating with a nucleating agent to obtain a transparent polylactic acid composite material, but the large amount of non-degradable transparent resin will also seriously affect the biodegradability of polylactic acid

[0006] The patent with the publication number CN 102838858A discloses a method for preparing a polylactic acid nucleating agent by compounding poly-L-lactic acid and poly-D-lactic acid; patent CN101602884B also reports the method of adding poly-D-lactic acid to improve the nucleating performance of PLA, but the price of poly-D-lactic acid is relatively high. Expensive, and D lactic acid is actually a monomer that does not exist in nature. D lactic acid was once used as a raw material for the synthesis of pesticides, although a small amount of poly D lactic acid can be added to ordinary poly L lactic acid to achieve a certain heat resistance effect , but its security needs to be further verified

[0007] The patent with the publication number CN105153659 A discloses a heat-resistant polylactic acid composite material and its preparation method, but the polylactic acid products prepared by this material need to be baked in an oven at 100-105°C for 0.5-2 hours after molding. Heat resistance, low efficiency, and the product is opaque

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