Study On Synthesis And Performance Of DCMB

Cyclopentadiene (CPD) molecule contains two conjugated double bond, which is prone to conduct Diels Alder reaction. Its methylene a-hydrogen atoms are active and can generate stable cyclopentadiene anion with active metal or strong alkali, so that CPD is widely used in the range of synthetic resin, rubber, pharmaceuticals, pesticides, spices and other chemical products. With the development of society and technology, CPD and its derivatives become a hot topic in the field of organic synthesis, the framework of the special structure of polymer, and fine chemicals, etc. Its application also constantly expands.This paper prepares1,4-bis (cyclopentadienylmethyl) benzene (DCMB), and characterizes its structure via IR and NMR. By changing the reaction condition it examines the optimal process of the experimental synthesis DCMB, nCPD-Na:nLb=2.06:1, the reaction temperature is room temperature for1h, nitrogen protection, with the result that DCMB yield up to71%by pulling out of small molecule substances under low pressure. DCMB molecular’s double ends are cyclopentadiene which are likely to auto-polymerize with pungent smell and turn to become light yellow liquid at loom temperature. When it auto-polymerizes and be oxidized at room temperature, its viscosity becomes high, liquid thickens and color gradually deepens changing from yellow to orange. Moreover, with the process of being sealed and stored under low temperature it can slow down the self-polymerization rate.By changing the reaction temperature and time, it implements DCMB’s aggregation in the absence of any catalysts, and determines the optimum process of PDCMB under the investigation of thermal performance Poly (1,4-bis (cyclopentadienylmethyl) benzene)(PDCMB) at the same time. After being vacuumized for30min, DCMB coarse product at80℃will be transferred to120℃vacuum mould processing for30min, and then pre-aggregated at120℃for60min, finally it will aggregate respectively at140℃,180℃,220℃for1h. In this way, the end product of PDCMB will have excellent heat resistance property with450"C thermal decomposition temperature,342℃when experiences5%weight loss,86℃when meets with glass transition, and possesses certain heat reversible property at170-200℃.This paper adopts the first generation Grubbs catalyst to synthesize DCMB (18%)-double loop pentadiene (DCPD) copolymer, and tested by TG, DSC, DMA, etc, and preliminarily studies DCMB effect on the thermal performance of DCPD. The copolymer thermal decomposition temperature is476℃,6.5℃higher than the thermal decomposition of PDCPD temperature. Copolymer thermal weightlessness temperature is232℃,95℃higher than PDCPD when experiences5%thermal weightlessness temperature. Moreover, carbon residue rate is nearly10%higher than PDCPD. Therefore, DCMB plays some role in improving the thermal decomposition temperature of PDCPD and fixing PDCPD monomer.