the free radicals reacted with the oxygen, which generated carbonyl groups, hydroperoxides and so on;the free radicals also had cross linking reaction, which generated alkoxy;

• （5）木塑复合材料的老化机理为：光和热引发木塑复合材料中木质组分和塑料组分大分子链断裂，产生的自由基与氧气作用，发生链支化反应生成羰基、氢过氧化物等，发生交联反应生成烷氧基等；