Mei Qilin

Mechanical and thermal properties of polysiloxanes and NBR blend elastomer

A series of elastomers, based on NBR, polysiloxanes (PS) were prepared and characterized by tensile tests, thermogravimetry (TG) and differential scanning calorimetry (DSC). Two kinds of vulcanizing agent, DMDBH (2,5-dimethyl-2,5-di(t-butyl perory) hexane) and DCP (dicumylperoxide) were used to investigate the influence of different vulcanizing agents on properties of PSINBR. The addition of PS to NBR was found to improve the thermal stability and decrease the tensile strength of NBR. The tensile strength decreased considerably while the elongation at break increased obviously with the increase of PS content. The series using DMD-BH as vulcanizing agent showed a higher tensile strength and elongation at break than the series using DCP as vulcanizing agent. Simultaneity the thermal stability increased with the increase of PS content.

Preparation of the heat resistant adhesive of NBR modified BMI

A Kind of homogeneous resin, which can be used as thermal resistant adhesive and matrix for composite, was prepared by bis (4-maleimidophenyl) methane (BMI), 4, 4′-diaminodiphenylmethane (DDM), aniline (An), phenol type epoxy resin (F-51) and nitrile-butadiene rubber (NBR) through solution copolymerization. The reaction from prepolymerization to curing of the resin system was studied. And the factors such as raw material ratio and curing temperature, which affect thermal resistance and adhesives of cured product, were also analyzed. SEM and IR spectra were utilized to discuss the mechanisms of toughness and reaction of modified BMI.

Numerical Simulation of Phenolic Sheet Molding Compound in Compression Molding

Based on generalized Hele-Shaw (GHS) model, a numerical simulation of phenolic sheet molding compound (P-SMC) in compression molding is realized by finite element step-by-step computing method. Finite elemental computing and post analysis programs have been written. The compression mold filling process, time and pressure requirements of P-SMC in a closed mold are predicted, and a good agreement is shown when compared with experiments. It will be of theoretical significance for the mold design and the optimization of the technological parameters in the compression molding of sheet molding compound.