Polylactic acid nucleating agent, preparation method and application thereof

Abstract

The invention relates to the high polymer material field, particularly referring to a novel polylactic acid nucleating agent, a preparation method and an application thereof. The novel polylactic acid nucleating agent comprises following materials by weight: 40-60 parts of poly L-lactic acid, 40-60 parts of poly D-lactic acid, 0.01-5 parts of stabilizer and 0.5-20 parts of reactant. The nucleating agent has simple preparation method; the polylactic acid nucleating agent has the advantages of stable molecular weight, uniform molecular weight distribution and good eutectic structure; the preparation method can effectively improve crystallization rate of polylactic acid, and obtain polylactic acid product with excellent chemical resistance, heat resistance and better transparency; and therefore, the nucleating agent has wide development and application prospect in preparation of the polylactic acid product.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a novel polylactic acid nucleating agent and its preparation and application. Background technique [0002] Polylactic acid (PLA) is a polymer with excellent biocompatibility, which is derived from renewable resource crops (such as corn). The most prominent advantage is biodegradability, which can be completely destroyed by microorganisms in nature after use. It degrades and finally produces carbon dioxide and water, which does not pollute the environment and is very beneficial to the protection of the environment. Polylactic acid has good mechanical properties, thermoplasticity, fiber formation, and high transparency. It is suitable for various processing methods such as blow molding and thermoplastic, and is easy to process. It is defined by the industry as the most promising new material in the new century. However, as an engineering plastic, polylactic acid has the disadvant...

AI Technical Summary

Problems solved by technology

Inorganic nucleating agents mainly include montmorillonite, TiO2, CaO, MgO, BaSO4, SiO2, Al2O3, etc. The advantage of this type of nucleating agent is that it can reach nano-scale particle size, but there is a problem of agglomeration in use, and it is difficult to maintain uniform dispersion at the nanoscale

[0003] Patent CN1366004 uses a twin-screw extruder to blend nucleating agents and polyester materials, which improves the dispersion of nucleating agents and increases the crystallization speed of polyester. However, for biodegradable materials, thermal degradation is severe during processing, which increases crystallization. The speed also reduces the molecular weight

[0004] Patent application No. 201080032592.5 prepared a stereocomplex of polylactic acid and declared that it can be used as a nucleating agent, but the stereocomplex was mixed with traditional organic and inorganic nucleating agents during the synthesis process. When nucleating agents are used, it is difficult to prove that their nucleating effect is not derived from these added traditional nucleating agents

Moreover, the polylactic acid stereocomplex contains more terminal groups, which will cause thermal degradation of itself and the matrix resin when it is melted and mixed with the polylactic acid resin. If the degradation is severe, it will seriously affect the performance of the product.

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