流场特性对熔融混合条件下PVDF/HGMs性能影响

The Influence of Flow Field Characteristics on the Performance of PVDF/HGMs Under Melting and Mixing Conditions

利用剪切形变支配的Brabender转子密炼机(BM)和自行研制的拉伸形变支配的叶片混炼机(VM),采用熔融共混法制备PVDF/HGMs共混物,通过对比分析了流场特性对共混物微观结构、力学性能和介电性能的影响。密度测试与SEM结果表明,当HGMs含量为15%时,采用BM和VM制备的共混物密度分别降低了10%和13%,拉伸流场起主导作用的VM对HGMs结构的损害较小,未进行任何处理的HGMs在基体中分散均匀,并且与基体形成了稳固的结合界面;当HGMs含量为9%时,VM制备的共混物的拉伸强度为43.2 MPa,与BM制备的共混物相比,提高了39.8%;VM制备的共混物的介电损耗为0.063,与BM制备的共混物相比,降低了25%。因此,VM在熔融共混制备的过程中,在实现了HGMs良好分散的同时,保存了HGMs的完整性。

The Brabender rotor mixer(BM)dominated by shear deformation and the self-developed Vane mixer(VM)dominated by tensile deformation were used to prepared PVDF/HGMs blends by melt compounding.The effect of the flow field characteristics on the microstructure,mechanical properties and dielectric properties of the blends was compared and analyzed.Density test and SEM photos showed that when the content of HGMs is 15%,the density of the blends prepared by BM and VM decreases by 10%and 13%,which indicated VM dominated by the extensional flow field caused less damage to HGMs.Meanwhile,HGMs were uniformly dispersed in the matrix and form a stable bonding interface with the matrix when HGMs were not treated.When the content of HGMs was 9%,the tensile strength of the blend prepared by VM was 39.8%higher than that of BM and the dielectric loss of the blend prepared by VM was 25%lower than BM.The comprehensive results showed that VM could efficiently disperse and mix fillers in melt-prepared blends,and preserve the integrity of easily broken and fractured fillers.