Study on Preparation of Novel Dicyclopentadiene Phenol Epoxy Resin Materials Based on Different Degrees of Polymerization

This paper briefly describes the relevant properties of epoxy resin materials, and introduces the domestic and international progress of dicyclopentadiene (DCPD) phenolic epoxy resin. The process conditions of dicyclopentadiene phenol resin and epoxy resin were studied. Dicyclopentadiene phenol epoxy resin with different degrees of polymerization was prepared. The reaction heat was measured and the curing temperature, time and curing were analysed. The influence of factors such as the agent structure on the gel time and curing degree of DCPD phenol epoxy resin; the effects of temperature and time on the curing reaction of DCPD phenol epoxy resin were discussed.

Investigation of the mechanical and flame retardant properties of carbon fiber modified phenolic epoxy resin

Epoxy resin and carbon fiber were used as the reinforcement to modify phenolic resin. Phenolic epoxy resin was prepared by physical blending, and carbon fiber was introduced into the resin matrix, and meanwhile the curing agent was added. The flame retardancy and thermal stability of the samples were evaluated, and the mechanical performance of the samples was characterized to investigate the overall performance. The flame retardancy of phenolic epoxy resin decreased slightly with epoxy resin of 5 wt%. The oxygen index was decreased by 6.3%, the ignition time was shortened by 66 s, and the peak heat release rate was increased by 8.9%. The tensile strength and elastic modulus were increased by 46% and 26.1%, respectively. The flame retardant and mechanical properties of phenolic epoxy resin were improved the most with short carbon fiber of 0.5 wt%. The oxygen index was increased by 4.6%, the ignition time was delayed by 35 s, the peak heat release rate was reduced by 18.9%, the carbon residue rate at 800℃ was increased by 60.4%, the apparent activation energy was increased by 11.3%, and the tensile strength and elastic modulus were improved by 90.4% and 87.9%, respectively.

Matt Polyurethane Coating: Correlation of Surface Roughness on Measurement Length and Gloss

Matt polyurethane coating was successfully prepared through the synergistic effect of castor oil and phenolic epoxy resin into polyurethane backbone. The formation mechanism may be ascribed to the modulus mismatch between the partially modified epoxy polyurethane and partially unmodified polyurethane. Scanning electron microscopy (SEM) was used to observe the micro-rough surface morphologies. Atomic force microscopy (AFM) and three-dimensional (3D) surface profilometer were applied to calculate a series of surface roughness parameters in different dimensions, such as Sa, Sq, Sp, Sv, Sz, Sku, Ssk, etc. The exciting results of this paper—the correlation of surface roughness on measurement length and gloss—are explored in detail. It reveals the extrinsic property of measured roughness with measurement length and provides guidance for what kind of incident angle gloss meters (20°, 60°, and 85°) best describe the gloss of matt polyurethane coating.

Study on the Phenolic - Epoxy Resin System

By blending the different ratio of the low viscosity of bisphenol A type epoxy resin with low viscosity ammonia catalytic phenolic resin, the performance of the resin systems were investigated by the gel time, viscosity, mechanical properties, heat resistance, flame retardance. In addition, DSC was used to detect the thermal property, and FT-IR monitored the reactive process of phenolic-epoxy resin. When the phenolic resin was mixed with 5% epoxy resin, the results were as follow: the gel time of 121 s at 150°C, viscosity of 7760 mPa·s at 30°C, flexural strength of 83.3 MPa, impact strength of 6.9 kJ/m2, tensile strength of 20 MPa, heat deflection temperature of 148.5°C, oxygen index of 34.5% and the apparent cure activation energy of 94.2kJ/mol. The resin systems had higher service temperature, low viscosity, excellent mechanical properties and service characteristics, and it could meet the requirements of fast pultrusion process.