In the present work weathering peculiarities for heat-treated wood plastic composites (HTWPC) were investigated mainly focusing on the effects caused by UV radiation. In addition, the discolouration mechanism for WPC was analysed in general. The results showed that the colour change during UV exposure for WPC with untreated wood particles (WPC_(UT)) initially is caused by wood particle discolouration, which is followed by rapid increase in lightness that is due to polypropylene photodegradation. For HTWPC initial colour change caused by heat-treated wood particles was insignificant, however eventually the discolouration for the composite was several times larger than for WPC_(UT) due to polypropylene photodegradation in combination with darker initial colour of the composite. Microcracking that reduce the light transmittance of the polypropylene matrix was the main reason for the large colour change. Despite the larger discolouration, the results regarding surface erosion and microcracking showed that HTWPC are more resistant against UV radiation.

在目前的工作中，对热处理木塑复合材料（HTWPC）的风化特性进行了研究，主要集中在紫外线辐射引起的影响上。另外，一般分析了WPC的变色机理。结果表明，未经处理的木材颗粒（WPC _（UT））在WPC暴露于紫外线期间的颜色变化最初是由木材颗粒变色引起的，随后由于聚丙烯的光降解而使亮度迅速增加。对于HTWPC，由热处理的木材颗粒引起的初始颜色变化微不足道，但是最终复合材料的变色比WPC _（UT）大几倍。由于聚丙烯的光降解作用，加上复合材料的初始颜色较深。降低聚丙烯基体透光率的微裂纹是产生较大颜色变化的主要原因。尽管变色较大，但有关表面腐蚀和微裂纹的结果表明，HTWPC对紫外线的耐受性更高。