Study On Reinforcing And Modification Of Polydicyclopentadiene

Polydicyclopentadiene (poly-DCPD) is a kind of thermoset resin with good processing properties and mechanical properties. Recent researches focus on improving the mechanical and thermal properties of poly-DCPD. Methods including copolymerization and adding nanofillers are mainly used to modify poly-DCPD.Poly-DCPD was prepared with the first generation Grubbs' catalyst through ring-opening metathesis polymerization (ROMP). BMI reinforced poly-(OXDBMI/DCPD) was prepared with Oxadiazole-containing bismaleimide (OXDBMI) and DCPD. Mechanical and thermal properties of the copolymers were studied. The results showed that the thermal stability of poly-(OXDBMI/DCPD) was better than Poly-DCPD. And the thermal resistance of poly-(OXDBMI/DCPD) improved with increasing OXDBMI content. The storage modulus (G') of poly-(OXDBMI/DCPD) significantly increased comparing to the unfilled poly-DCPD, both the G'and Tg of poly-(OXDBMI/DCPD) rose up with increasing content of OXDBMI. Otherwise, the impact strength of poly-(OXDBMI/DCPD) sharply declined.Grinding glass fiber (MG) was added into poly-DCPD in order to inhance the mechanical and thermal properties of poly-DCPD. Mechanical and thermal properties of the MG/poly-DCPD composites were studied. The results showed that tensile modulus and bending modulus of the composites increased while longation at break declined with increasing content of MG. The tensile strength and bending strength of the composites increased at first and then decreased with increasing MG content. The impact strength of MG/poly-DCPD declined compared with unfilled poly-DCPD. DMA results showed that storage modulus (G') of MG/poly-DCPD increased with increasing MG content. MG/poly-DCPD composite had single glass trasition and its Tg rose up with increasing MG content. Thermal performance of MG/poly-DCPD also enhanced with an increasing amount of MG. When adding 20 wt% MG, the Tdmax increased from 465.4? to 479.5? and the residual weight at 800? increased by 106.7%.Silane coupling agent KH-570 was used to modify the suface of milled glass fiber, in order to improve the interfacial compatibility of MG/poly-DCPD. The effects of coupling agent content on the properties of CMG/poly-DCPD composite were studied. When filling content of KH-570 was 0.6wt% of MG, the tensile strength, bending strength and bending modulus respectively reached their maximum values. The impact strength has increased by 60.5% at the same KH-570 content. When adding 25 wt% CMG, the tensile strength of CMG/poly-DCPD reached 58.23 MPa, which was 18.1% higher than unfilled poly-DCPD. The bending strength of CMG/poly-DCPD has no significant improvement compared to unfilled poly-DCPD. The impact strength of CMG/poly-DCPD was higher than that of MG/poly-DCPD, and it also improved with increasing content of CMG. When adding 10 wt% CMG, the impact strength of CMG/poly-DCPD reached 143.15kJ/m2, which was 25.1% higher than unfilled poly-DCPD. However, more than 10% CMG declined the impact strength of CMG/poly-DCPD.