水滑石填充PVC复合材料的制备及性能研究

Preparation and Performance of Hydrotalcite-filled PVC Composites

采用液态丁腈橡胶(LNBR)对水滑石(HT)进行表面包覆改性制备了LNBR/HT,并用其填充聚氯乙烯(PVC)制备了复合材料,采用红外光谱仪(FTIR)简支梁冲击试验机、万能试验机、氧指数测定仪、动态力学分析仪(DMA)、、扫描电子显微镜(SEM)等仪器研究了LNBR对HT的改性方式和改性前后HT含量对复合材料力学性能、阻燃性能、动态力学性能及微观形貌的影响。结果表明,LNBR对HT的改性为物理改性,由于LNBR与PVC基体有良好的相容性,经LNBR改性的HT在PVC基体中的分散性得以改善,其与PVC基体的界面黏结作用增强;PVC/LNBR/HT复合材料较PVC/HT表现出优异的力学性能和阻燃性能;PVC/LNBR/HT复合材料的拉伸强度和缺口冲击强度在LNBR/HT含量分别为5份和10份时分别达最大值,为29.8 MPa和17.7 kJ/m2;PVC/LNBR/HT复合材料的极限氧指数在LNBR/HT含量为40份时达34.6%;由于LNBR在复合材料体系中充当增容剂和增塑剂的双重作用,PVC/LNBR/HT复合材料的刚性增加,但耐热性出现小幅下降。

In this work,hydrotalcite(HT)was surface modified with a liquid nitrile rubber(LNBR). The resultant LNBR-modified HT was filled into poly(vinyl chloride)(PVC)to prepare PVC/LNBR-modified HT composites. The modification of HT by LNBR,the effect of the content of HT before and after modification on the mechanical properties,flame retardant properties,dynamic mechanical properties and micro morphology of the composites was investigated using,infrared spectrometer simply supported beam impact testing machine,universal testing machine,oxygen index tester,dynamic mechanical analyzer and scanning electron microscope. The results indicated that the surface modification of HT with LNBR belonged to a physical modification. Own to good compatibility between LNBR and the PVC matrix,the dispersibility of LNBR-modified HT in the PVC matrix was improved,and the interfacial adhesion between LNBR and the PVC matrix was enhanced. The PVC/LNBR-modified HT composites exhibited better performance than that of the PVC/unmodified HT composites. The PVC/LNBR/HT composites achieved maximum tensile strength of 29. 8 MPa and maximum notched impact strength of 17. 7 kJ/m2 with the addition of 5 phr and 10 phr of LNBR-modified HT,respectively. Moreover,the PVC/LNBR/HT composites presented an limiting oxygen index of 34. 6 vol% with the addition of 40 phr LNBR-modified HT. LNBR plays dual roles as compatibilizer and plasticizer in the PVC/LNBR/HT composites. This leads to an increase in rigid,but a decrease in heat resistance.