Study On Interpenetrating Network Of Dicyclopentadiene/Polystyrene

Polycyclopentadiene (PDCPD) which is obtained by Dicyclopentadiene (DCPD) withring-opening metathesis polymerization (ROMP) is one of the novel types of highperformance engineering plastics and it has been a hot in the field of polymer materials.The high rate and strong exothermicity of ring-opening metathesis polymerization ofdicyclopentadiene, which is especially suitable to reaction injection moulding, may beused to design a novel method of preparing simultaneous interpenetrating polymernetworks with controllable structure. According to mechanism of ring-openingmetathesis polymerization and mechanism of radical polymerization respectively,dicyclopentadiene and vinyl monomer can simultaneously and rapidly polymerize toform a interpenetrating polymer networks structure with compatible or incompatiblepolymers to polydicyclopentadiene. The synergetic action of different polymers willendow the products with some special properties. Therefore, different structure of IPN,even functional polymer alloy may be fromed by selecting monomer species, changingcomposition ratio, using a variety of vinyl monomer synchronously and so on. In thisway, the performance of PDCPD can be further expanded.In the ROMP catalyst system, this paper studied the polymerization reactioncharacteristics between DCPD and styrene (St), as well as bromostyrene (BSt), andprepared a different content of polycyclopentadiene/polystyrene (PDCPD/PS),Polycyclopentadiene/Polybromostyrene (PDCPD/PBSt) composite materials. Incontrast, this paper made brominated polystyrene (BPSt) dissolved in DCPD andprepared PDCPD/BPSt composite material with the method of in-situ blends. Thecomposite structure was analysised and characterized by extractiono, IR, SEM, DSC,TG, et al. and the mechanical propeties and flame retardance ablity were tested bytensile testing machine, impact testing machine as well as the oxygen index machine. The study found that the heat released by DCPD ROMP could trigger St and BStthermal polymerization, and the conversion rate of St and BSt were high. Furthermore,St and BSt could promote the polymerization of DCPD, whereas BPSt could not. Theextraction, IR indicated St could homopolymerization for PS, and its molecular resinwrapped around the PDCPD network and formed PDCPD/PS semi-IPN structure. Inthe same way, we prepared PDCPD/PBSt semi-IPN structure.In PDCPD/PS system, mechanical test results within the measuring range illustratedthe mechanical propeties showed an increasing trend with the increasing of St. Thetensile strength and impact strength of composite materials enhanced32.5%and33.3%than pure PDCPD respectively. In PDCPD/PBSt and PDCPD/BPSt systems, theimpact strength decreased with the increasing of BSt or BPSt, while the tensilestrength reached a peak when mass fraction of BSt or BPSt was about10%,respectively28.33MPa and30.76MPa. The flame retardant tests showed the flameretardant properties improved significantly with the increasing of BSt or BPSt withinthe measuring range.