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以高密度聚乙烯(HDPE)和木粉为原料,辅以少量化学助剂,采用共挤出生产工艺,以芯层木塑比为6∶4,壳层添加不同含量纳米白炭黑制备出核-壳结构木塑复合材料(WPC)。将其放入老化箱进行紫外光加速老化试验,并对表面颜色、表面形貌、抗弯性能及化学成分进行了测试和表征。结果表明,紫外老化2 500 h后,较之空白样,加入2%纳米白炭黑的ΔE下降了32.7%,试样表面更加完整,裂纹与粉尘较少;弯曲强度保留率提高了9.9%,弹性模量保留率提高了13.2%,且均优于1%纳米白炭黑试样;所有材料表面的氧(O)/碳(C)含量比(n_O/n_C)与老化后木塑表面氧化的碳(C_(ox))/未氧化的碳(C_(unox))的含量比(n_(C_(ox))/n_(C_(unox)))均增大,表面氧化程度加深;其中添加2%纳米白炭黑的WPC表面氧化程度最低,n_O/n_C增长幅度为15.5%,n_(C_(ox))/n_(C_(unox))增加了16.5%,均低于空白样与1%纳米白炭黑试样。说明纳米白炭黑能够提高核-壳WPC抗紫外老化性能并降低其光氧化降解程度,并且适当提高添加量效果更佳。
High-density polyethylene (HDPE) and wood flour as raw materials, supplemented by a small amount of chemical additives, the use of co-extrusion production process, the core layer plastic ratio of 6: 4, the shell was added to prepare a different content of nano-silica Core-shell structure WPC. The samples were placed in an aging chamber and subjected to UV accelerated aging test. The surface color, surface topography, flexural properties and chemical composition were tested and characterized. The results showed that the ΔE decreased by 32.7% compared with the blank sample after 2 500 h UV aging, and the surface of the sample was more complete with less cracks and dust. The retention of flexural strength increased by 9.9% The retention of elastic modulus increased by 13.2%, and both were better than that of 1% nano-white carbon black. The oxygen (O) / carbon (C) content ratio (n_O / n_C) The content ratio (n_ (C_ (ox)) / n_ (unox) of carbon (C_ox) / unox (Cox) increased and the degree of surface oxidation deepened. The WPC surface oxidation of 2% nanosilica was the lowest, with n_O / n_C increasing by 15.5% and n_ (Cox / nox) by 16.5%, both of which were lower than that of blank and 1% Nanometer white carbon black sample. Nanosilica can improve the core-shell WPC UV aging resistance and reduce the extent of their photooxidative degradation, and the appropriate increase in the amount of added better.