The Study Of Functional Fillers On The Damping Improvement Of Acrylate-based Composites

Polymer based damping materials have attracted considerable attention in all fields due to their outstanding properties for reducing vibration and noise.In this dissertation,acrylic rubber(polyacrylate)was choosed as matrix,and phenolic resin(PF),polyhedral oligomeric silsesquioxanes(POSS)were used as functional fillers.The acrylate-based composites with PF or POSS were prepared by solution blending and in-situ emulsion polymerization,respectively.Meanwhile,the structure and the damping properties of the composites were characterized by FTIR,SEM,XRD,DSC and DMA.For AR/PF systems,we focused on the effects of chemical structure of PF and hot-pressing process on dynamic mechanical properties.For OVPOSS-P(BA-MMA)systems,the effects of crosslinking density on dynamic mechanical properties were investigated systematically.Furthermore,different types of POSS and preparation methods were also introduced.For AR based composites with resol resin(AR/Rr),we found that the addition of Rr could decrease the loss factor and shift the loss peak to a low temperature.After curing,the loss peaks totally moved toward high temperature and the tan 8 peak height continued to decrease dramatically.In contrast,novolac resin(Nr)would broaden the effective damping temperature region(tan ?max=1.95)and raise the temperature of tan 8 peak(from-7 ? to 23.8 ?)after hot-pressing,because of forming hydrogen bonding with polar matrix.So we confirmed that the Nr was a great help to improving the damping properties of AR at room temperature.For OVPOSS based composites,in-situ polymerization would cause a fine dispersion of functional fillers.OVPOSS was used as a crosslinking agent.When the OVPOSS content increased to 7 wt%,the Tg reached to 18.5 ? as well as a slightly decrease in tan ? value.These nanocomposites were suitable for utilization in room temperature.Furthermore,OVPOSS would also make a great improvement on mechanical property and thermal stability.As a result,Nr and OVPOSS are efficient as functional fillers to improve the damping properties of AR at room temperature.