Blocked diisocyanate polyester-toughened novolak-type phenolic resin: Synthesis, characterization, and properties of composites

✍ Scribed by Chen-Chi M. Ma; Han-Thing Tseng; Hew-Der Wu

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 283 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980808)69:6<1119::aid-app9>3.0.co;2-j

✦ Synopsis

A blocked diisocyanate polyester was synthesized to copolymerize with novolak-type phenolic resin. From the results of IR and NMR spectra, it was found that the blocked diisocyanate polyester reacts with the hydroxyl group of the novolak-type phenolic resin at high temperature. The deblocking temperature for the novolak-type phenolic resin is 120ЊC. The blocking agent, 1-caprolactam, is convenient for this system. The copolymer exhibited a single glass transition temperature and a negative deviation of the glass transition temperature. The results showed that the copolymer system is miscible and the molecular motion of the copolymer is increased with the addition of a modifier. The interface between the modified phenolic resin and the glass fiber is improved and the tensile strength of pultruded composite is increased with the modifier content.