Number Of Epoxy Groups Research Articles

Molecular design of an epoxy for cryogenic temperatures

The mechanical and thermal properties of several epoxy resins were measured to obtain guidelines for the molecular design of an epoxy resin for cryogenic temperatures. Two types of epoxy resin with different numbers of epoxy groups were mixed (with different mixing ratios) and cured. Fracture toughness, flexural strength and thermal contraction of the hybrid epoxy resins were measured down to cryogenic temperatures. The results suggest that epoxies with larger molecular weights between crosslinkings relaxed stress at the crack tip, even at cryogenic temperatures. Intermolecular forces and stress relaxation at the crack tip were found to be important for high fracture toughness.

極低温用エポキシ樹脂の高靭性化の試み

Hybrid materials involving epoxies with different numbers of reactive groups have been prepared to determine the molecular design of epoxies with high fracture toughness at cryogenic temperatures. To answer the opponent demands, that is, strong and flexible chains, hybrid materials were proposed. Two types of epoxy resin with different numbers of epoxy groups were mixed and cured by changing the mixing ratio. Fracture toughness, flexural strength, dielectric loss tangent, and thermal contraction of the hybrid epoxy resins were measured down to cryogenic temperatures. A hybrid material with high fracture toughness, even at liquid helium temperature, was successfully developed and hence the molecular design orientation was confirmed to be possible.

エポキシ化合物に関する研

Four new epoxy resins were obtained by the reaction of epichlorohydrin and the phenolalkylbenzene-formaldehyde resins such as phenol-xylene-formaldehyde resins or phenol-C9 or C10-alkylbenzene-formaldehyde resins.The number of epoxy groups in the epoxy resin obtained corresponds to the amount of oxygen in the alkylbenzene-formaldehyde resin. It is assumed that the obtained epoxy resins have the general molecular structures as follows:where n=1, 2 and 3, R=H or CH3.This epoxy resin cured with diaminodiphenylmethane had a heat distortion temperature of 150°C or more. Monoepoxide obtained from xylene-formaldehyde resin was examined as a reactive diluent for epoxy resins obtained from bisphenol A and epichlorohydrin.