Properties and Curing Behavior of Urea-Modified Phenolic Resins

• 영문명: Properties and Curing Behavior of Urea-Modified Phenolic Resins
• 발행기관: 한국응용과학기술학회 (구.한국유화학회)
• 저자명: Lee SangMin Park SangBum Park JongYoung
• 간행물 정보: 『한국응용과학기술학회지』한국유화학회지 제24권 제4호, 339~346쪽, 전체 8쪽
• 주제분류: 공학 > 화학공학
• 파일형태: PDF
• 발행일자: 2007.12.31

영문 초록

The influence of adding urea to phenol-formaldehyde (PF) resins as a co-polymer component were investigated aiming at synthesizing useful phenol-urea-formaldehyde resins. Urea was added at 10% by total resin weight. Several methods for the addition of urea to the PF resins during synthesizing resins to see the co-polymerization occurs between urea and PF resins. The urea was added at the beginning, at three different middle stages, and at the end of PF resin synthesis. The copolymerized methylene bridges between phenol and urea molecules were not observed by ^{13}C-NMR;no signal around 50ppm. The curing of urea-modified PF resins, evaluated by dynamic mechanical analysis(DMA), showed some differences among the resins. DMA gel times ranged from 2.75 min to 3.25 min and the resins made with earlier urea additions showed slightly shorter gel times. The longest cure time and gelation time was observed for the resin PFU. Catalyst effects on the DMA cure time values of resins were not significant with different amounts of catalyst or different types of catalyst for all resins tested. Gel times of urea-modified PF resins shortened the most by triacetin catalyst

키워드

phenol-formaldehyde resins urea catalysts co-polymerization$^{13}C-NMR urea-modified PF resins dynamic mechanical analysis