National Science Council

Hew-Der Wu

Chen-Chi Martin Ma

Chih-Tsung Lee

Ming-Shiu Li

Modified resole and novolac type phenolic resins which are toughened by poly(alkylene oxide) are disclosed. The modified resole type phenolic resin is prepared by the following steps: mixing a poly(alkylene oxide) having a weight average molecular weight of 100,000.about.8,000,000 and phenol in a weight ratio of poly(alkylene oxide): phenol=1.5:1.about.1:1 at an elevated temperature to form a glutinous mixture; mixing the glutinous mixture with an acid catalyst to obtain a viscous mixture having a relatively low viscosity compared to the glutinous mixture; and mixing the viscose mixture with a resole type phenolic resin. The modified novolac type phenolic resin is prepared by directly mixing the glutinous mixture with a liquid novolac type phenolic resin. The amount of the poly(alkylene oxide) mixed is 2.about.10 wt % based on the phenolic resin.

Modified phenolic resin toughened by poly (alkylene oxide) and

A modified phenolic resin which is toughened by phenoxy resin is disclosed. The modified phenolic resin is prepared by the following steps: mixing a phenoxy resin having a weight average molecular weight of 10,000-1,000,000 and phenol in a weight ratio of phenoxy resin:phenol=1.5:1-1:1 at an elevated temperature to form a glutinous mixture; mixing the glutinous mixture and an acid catalyst to obtain a viscous mixture having a relatively low viscosity compared to the glutinous mixture; mixing the viscose mixture and a resole type phenolic resin to form a modified phenolic resin, wherein the resole type phenolic resin has a solid content of 60--75 wt. % and a free aldehyde content of 5-10 wt. %, the amount of the acid catalyst mixed is 2-10 wt. %, and the amount of the phenoxy resin mixed is 3-25 wt. % based on the resole type phenolic resin.

Modified phenolic resin toughened by phenoxy resin

A method for the preparation of a fiber reinforced modified phenolic resin composite, which comprises preparing a resole type phenolic resin having 60-75 wt % solid content and 5-10 wt % free aldehyde; preparing a blocked polyurethane resin having an average molecular weight of 2000-8000 and a viscosity of 500-1000 cps at 80.degree. C.; mixing the resole type phenolic resin, the blocked polyurethane resin and an acid catalyst at room temperature to form an impregnating resin, wherein the amount of the acid catalyst mixed is 2-10 wt %, based on the weight of the resole type phenolic resin, and the amount of the blocked polyurethane mixed is 5-20 wt %, based on the total weight of the mixed resins; and impregnating a plurality of filaments with the impregnating resin, and curing the impregnated filaments with a heat treatment to form a fiber reinforced modified phenolic resin composite.

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Hsinchu, Taiwan

Hew-Der Wu