Influence of a bark-filler on the properties of PLA biocomposites - dataset

In this study, WPC composites made of PLA and a bark-filler were manufactured. Two degrees of bark comminution (10 – 35 mesh and over 35 mesh) and varied content of bark (40, 50 and 60%) were investigated. The studied panels were compared with analogically manufactured HDPE boards. The manufacture of composites involved two stages: at first, WPC granules with the appropriate formulation were produced using the extruder (temperatures in individual extruder sections were 170°C - 180°C) and crushing at hammer mill after cooling the extruded composite; secondly, the obtained granulate was used to produce boards with nominal dimensions of 300x300x2.5 mm3 by flat pressing in a mold, using a single-shelf press at a temperature 200oC. The study proved that comminuted bark can be applied as a filler in PLA composites. However, an increase in bark content decreased mechanical properties (MOR, MOE) and deteriorated humidity resistance (high TS and WA) of the panels. Along with the increase in bark content, an increase in the contact angle of the composite surfaces and a decrease in the total surface energy were noted. It was also found that PLA composites have higher strength parameters and lower moisture resistance compared to HDPE composites with the same bark content. content.

本研究制备了以聚乳酸（PLA）和树皮填料为原料的木塑复合材料（WPC）。考察了两种树皮粉碎粒度（10~35目及35目以上）以及不同树皮添加量（40%、50%和60%）的试样，并将所制备的板材与采用相同工艺制备的高密度聚乙烯（HDPE）板材进行了对比。复合材料的制备分为两个阶段：第一阶段，采用挤出机制备符合配方要求的木塑复合材料粒料（挤出机各段温度设置为170℃~180℃），待挤出的复合材料冷却后通过锤式粉碎机进行粉碎；第二阶段，将所得粒料置于模具中，通过单压板热压机在200℃条件下进行平板热压，制备标称尺寸为300mm×300mm×2.5mm的板材。研究表明，经粉碎处理的树皮可作为填料应用于聚乳酸基复合材料中。然而，树皮添加量的提升会降低板材的力学性能（抗弯强度MOR、弹性模量MOE），并恶化其耐湿热性能，表现为较高的厚度膨胀率TS与吸水率WA。同时，随着树皮添加量的提升，复合材料表面的接触角增大，总表面能降低。此外还发现，在树皮添加量相同的情况下，聚乳酸基复合材料的强度参数优于高密度聚乙烯基复合材料，但耐湿热性能更差。