共挤出型芯—表结构木塑复合材料弯曲性能与热膨胀性能的研究

Flexural and Thermal Expansion Properties of Core-shell Structure Wood Polymer Composites

以改性玻璃纤维(GF)为表层的增强材料,以共挤出技术为加工工艺,制备了芯-表结构的木塑复合材料,分析了其在芯层1和芯层2两种复合体系下的弯曲和热膨胀性能。结果表明:当表层GF加入量为0时,即为表层为纯高密度聚乙烯(HDPE)时,无论是在芯层1还是芯层2的复合体系,芯—表结构木塑复合材料的线性热膨胀系数(LTEC)高于芯层材料,其弯曲模量和弯曲强度均小于芯层材料;芯—表结构木塑复合材料(GF增强表层)的弯曲强度、模量随着表层GF加入量的增加而增加;芯—表结构木塑复合材料的热膨胀性能是表层和芯层性能共同作用的结果,在表层加入GF后,其表层材料的热膨胀系数和芯—表结构木塑复合材料同时降低,且降低趋势相近。

Experiments were conducted on different modified glass fiber（GF） content on flexural and thermal expansion performance of core-shell structure wood polymer composite（WPC） with GF-filled shells. The result demonstrated that WPC with pure high-density polyethylene（HDPE） shell had higher linear thermal expansion coefficient（LTEC） than the core＇s, but had lower bending modulus and strength. Bending modulus and strength of the composite increased but LTEC values decreased with increase of the GF loading levels in the shell. The experiments resulted that bending modulus/strength of core-shell structure WPC was greatly enhanced with unfilled- and filled HDPE shells.