Method for preparing micro-foaming poly lactic acid based wood-plastic composite with supercritical fluid

Abstract

The invention discloses a method for preparing a micro-foaming poly lactic acid (PLA) based wood-plastic composite with a supercritical fluid, and relates to the method for preparing the micro-foaming PLA based wood-plastic composite. The method aims at solving the problem that a PLA based wood-plastic composite which is uniform in bubble distribution, high in bubble density, small in bubble size and high in foaming ratio is difficultly obtained by the existing preparation method. The method comprises the steps that PLA, wood flour, a flexibilizer, a chain extender, a lubricant and a nucleating agent are mixed in a high mixing machine; melt blending is performed by a twin-screw extruder; an extruded molten mixture is placed in a pressure forming machine to obtain the PLA based wood-plastic composite; clipping is performed; swelling and permeation are performed in the supercritical fluid; and then temperature reduction and foaming are performed to obtain the micro-foaming PLA based wood-plastic composite. The micro-foaming PLA based wood-plastic composite is uniform in bubble distribution, high in bubble density, small in bubble size and high in foaming ratio. The method is mainly used for preparing the micro-foaming PLA based wood-plastic composite with the supercritical fluid.

Description

technical field [0001] The invention relates to a method for preparing microfoamed polylactic acid-based wood-plastic composite materials. Background technique [0002] Wood-plastic composite material is a new type of environmentally friendly composite material, but traditional wood-plastic composite materials have exposed shortcomings such as high product density and poor impact resistance, which severely limit the further development of wood-plastic composite materials. At the same time, the plastic matrix used is the five general-purpose plastics polyethylene, polypropylene, polyvinyl chloride, polystyrene and ABS. In recent years, the continuous shortage of petroleum resources has caused the cost of thermoplastics to continue to rise, resulting in the price of wood-plastic composite products. high. Therefore, the low density, low cost, and high performance of wood-plastic composite materials have become the goals that researchers at home and abroad have been pursuing. ...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the problem that it is difficult to obtain PLA-based foamed wood-plastic composite materials with uniform cell distribution, high cell density, small cell size, and high expansion ratio in the existing preparation methods, and provides a supercritical fluid preparation method. Method for microfoaming polylactic acid-based wood-plastic composites

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