Studies on Synthesis of Epoxy-Terminated Telechelic Poly(alkyl-phenylene oxide) and Its Curing Effects on DGEBA Epoxies

• Main Authors: Chia-Teh Su, 蘇家德
• Other Authors: Mong Liang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/81617067679095866012

碩士 === 國立嘉義大學 === 應用化學系研究所 === 97 === A series of dihydroxyl telechelic poly(alkyl-phenylene oxide)s (1) have been synthesized by oxidative polymerization of different types of alkylphenols with various aromatic diols in the presence of CuBr/dibutylamine catalysts. The novel telechelic derivatives based on aromatic diols as a core and 1 as arms were subsequently epoxidized with epichlorohydrin and a series of new epoxidized poly(alkyl-phenylene oxide)s (2) were accessible with number average molecular weight ranged from 1400 to 4500. The effects of epoxy-terminated telechelic poly(alkyl-phenylene oxide)s (2) on curing behaviour and thermal stability of diglycidyl ether of bisphenol-A epoxy (DGEBA) using 2-methylimidazole (2-MI), dicyandiamide (DICY), 4,4’-diamino-diphenylsulfone (DDS) and 4,4'-diamino- diphenylmethane (DDM) as curing agents are studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The effects of polymer 2 on curing behaviour and thermal stability of diglycidyl ether of bisphenol-A epoxy were presented in Table 2. It is observed that 2-MI reacts with epoxidized PPO and DGEBA at a faster rate (i.e., lower-temperature range) than does DDM, DICY and DDS, however, the order of thermal stability of the cured polymer is generally in the opposite direction, that is, DDS > DICY > DDM > 2-MI. The addition of polymer 2 generally leads to a significant increase in thermal stability and glass transition as compared to the pristine DGEBA cured epoxy analogues except for the cases of DDS curing agent in which the Tg of pristine DGEBA remained the highest. It is inferred that the rigidness and highly electron-attracting nature of the sulfone structure appeared to induce the amine functions have a delay reactivity and results in an incomplete curing reaction. It is also found that the increased molecular weight of telechelic epoxy would also enhance glass transition temperature of resultant curing products.