Wood polymer composites (WPCs) with core–shell structure reinforced with barite (BA)-filled high-density polyethylene (HDPE) shell layer were successfully fabricated, and their thermal expansion and mechanical properties were thoroughly analyzed. The incorporation of BA improved the flexural properties and reduced the impact strength and linear coefficients of thermal expansion (LCTEs) of the resulting composites, in comparison with unmodified HDPE. The use of relatively rigid pure HDPE with high LCTE values reduced the overall thermal stability and modulus of the WPCs. Both flexural properties and thermal expansion were significantly enhanced for BA-filled HDPE shells compared to the unmodified material. Thus, the novel core–shell layer showed a well-balanced performance. The employment of BA HDPE or unmodified HDPE layers as the shell for the WPC core significantly enhanced the impact strength of the co-extruded WPCs. The tensile modulus for BA-filled composite was predicted by the PPA-based model.

中文翻译：

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含有重晶石填充壳的核壳结构共挤木质聚合物复合材料的机械、易燃和热性能

成功制备了具有重晶石（BA）填充的高密度聚乙烯（HDPE）壳层增强的核壳结构的木质聚合物复合材料（WPC），并对其热膨胀和机械性能进行了深入分析。与未改性的 HDPE 相比，BA 的加入改善了弯曲性能并降低了所得复合材料的冲击强度和线性热膨胀系数 (LCTE)。使用具有高 LCTE 值的相对刚性的纯 HDPE 会降低 WPC 的整体热稳定性和模量。与未改性材料相比，BA 填充 HDPE 壳的弯曲性能和热膨胀均显着增强。因此，新型核壳层表现出良好的平衡性能。使用 BA HDPE 或未改性的 HDPE 层作为 WPC 芯的外壳显着提高了共挤出 WPC 的冲击强度。BA 填充复合材料的拉伸模量由基于 PPA 的模型预测。