超微粉煤灰填充高密度聚乙烯复合材料的制备与性能

Preparation and Properties of High-Density Polyethylene Composite Filled with Ultrafine Fly Ash

采用悬臂梁缺口冲击、差示扫描量热(DSC)、X射线衍射(XRD)和扫描电镜(SEM)等方法研究了蒸汽气流磨制备的超微粉煤灰(UFA)填充对高密度聚乙烯冲击强度、拉伸强度、弯曲强度和结晶度的影响。结果表明,未经表面处理的超微粉煤灰粒子可在聚乙烯中均匀分散;随着UFA含量从0phr增加至80phr,复合体系的刚性提高、结晶度增加,伸长率下降,但拉伸强度下降甚微(从21.76 MPa减少至19.65 MPa)。复合材料的冲击强度在超微粉煤灰添加量为60phr时从纯树脂的27.64 J/m2提高到60.54 J/m2,有大幅度的增加,超微粉煤灰具有明显的刚性粒子增韧作用。

Ultrafine fly ash （UFA） is a superfine, highly rigid filler with particle size about 5 μm, which is pulverized from fly ash by jet mill with overheated water steam. UFA/ high-density polyethylene （HDPE） composites were prepared and characterized. SEM test results show that unmodified UFA is homodipersed in HDPE matrix without aggregation. As the content of UFA increases from 0 phr to 80 phr, the stiffness, bending strength and crystallization degree of UFA/HDPE composites increase, the elongation decreases, the tensile strength of UFA/ HDPE composites just reduces a little from 21.76 MPa to 19.65MPa. Unlike common inorganic fillers, ultrafine fly ash remarkably improves the toughness of composites along with the rigidity. When UFA content is 60 phr, the notched impact strength of UFA/HDPE composite increases from original 27.64 J/m2 to 60.54 J/m2. Ultrafine fly ash has notable rigid filler toughening and reinforcing effect to HDPE resin.