核壳结构木塑复合材料抗紫外老化性能试验

发布时间：2018-09-03 09:22

【摘要】：以高密度聚乙烯(HDPE)和木粉为主要原料,采用传统木塑复合材料(WPC)制备工艺和共挤出生产工艺,分别制备出均一结构和核壳结构WPC。核壳结构WPC芯层原料配比与均一结构WPC相同(木塑质量比为6∶4),表层则为纯HDPE塑料。将两组材料进行紫外光加速老化试验,并对两组试件的表面颜色、表面形貌、化学基团及抗弯性能分别进行测试和表征。研究结果表明:经2 500 h紫外光照射后,均一结构与核壳结构的WPC表面颜色色差ΔE值分别增加17.59和9.40,核壳结构WPC的抗紫外色变能力明显优于均一结构WPC;电镜照片显示,与核壳结构WPC相比均一结构WPC表面粗糙,在紫外光作用下更容易出现表面裂纹和粉化现象;傅里叶红外光谱分析证明核壳结构WPC表面羟基与羰基基团变化明显低于均一结构WPC,HDPE表层有效延缓了WPC的光氧降解;随着紫外光老化时间延长,两组试件的抗弯性能均呈现下降趋势,经2 500 h老化试验后,核壳结构和均一结构WPC的弯曲强度保留率分别为58.1%和49.7%,弹性模量保留率分别为43.2%和38.0%,表明聚乙烯壳层结构对维持WPC强度有一定的积极作用。
[Abstract]:Using high density polyethylene (HDPE) (HDPE) and wood flour as main raw materials, WPC. with homogeneous structure and core-shell structure was prepared by using traditional wood-plastic composite (WPC) preparation process and co-extrusion production process, respectively. The material ratio of core-shell structure WPC core layer is the same as that of homogeneous structure WPC (the wood-plastic mass ratio is 6:4), and the surface layer is pure HDPE plastic. The surface color, surface morphology, chemical group and bending resistance of the two groups of samples were tested and characterized by UV accelerated aging test. The results showed that the color difference 螖 E value of WPC surface of homogeneous structure and core-shell structure increased 17.59 and 9.40 respectively after exposure to ultraviolet light for 2,500 h. The UV chromaticity resistance of core-shell structure WPC was obviously better than that of homogeneous structure WPC; electron microscope photo. Compared with the core-shell structure WPC, the surface of homogeneous WPC is rough, and the surface crack and pulverization are more likely to occur under the action of ultraviolet light. Fourier transform infrared spectroscopy (FTIR) analysis showed that the changes of hydroxyl and carbonyl groups on the surface of core-shell WPC were significantly lower than those of homogeneous WPC,HDPE, and the photooxidative degradation of WPC was effectively delayed with the increase of UV light aging time. The bending properties of the two groups of specimens showed a downward trend, and after 2 500 h aging test, The retention rates of flexural strength and elastic modulus of core-shell structure and homogeneous structure WPC are 58.1% and 49.7%, respectively. The retention rate of elastic modulus is 43.2% and 38.0%, respectively, which indicates that the structure of polyethylene shell has a positive effect on maintaining the strength of WPC.
【作者单位】：南京林业大学材料科学与工程学院;江苏省林业资源高效利用协同创新中心;
【基金】：国家“948”项目(2014-4-49) 江苏省优势学科二期建设项目(PAPD) 江苏省林业资源高效利用协同创新中心项目
【分类号】：TB332

【相似文献】