【摘要】 比较了N,N-二甲基苯胺(DMA)和N-甲基-N-2-羟乙基苯胺(HMA)对不饱和聚酯树脂的固化,HMA的固化时间比DMA的短,放热峰温度和巴士硬度比DMA的高。用HMA预促进的树脂比DMA的贮存稳定,凝胶时间漂移小。DSC等温扫描树脂固化过程,结果显示HMA固化放出的热量比DMA的多;玻璃化转变温度和固化程度比DMA的高。用自恰场密度泛函法对芳叔胺进行量化计算,HMA对树脂固化效果比DMA好的原因是羟乙基同氮原子形成分子内氢键,使氮原子上的孤对电子同苯环共轭程度不如DMA,从而减少了氮原子电子密度的降低,其亲核反应能力比DMA高,有利于过氧化物分解形成自由基。更多还原

【Abstract】 N-2-hydroxyethyl-N-methy-laniline(HMA) was compared to N,N-dimethyl aniline(DMA) as cure reaction promoters for an unsaturated polyester resin.It was found that for benzoyl peroxide(BPO) initiation at room temperature,HMA is efficient than the more commonly used DMA,as indicated by decreased cure times or increased peak exotherm and barcol hardness.HMA was used with good results instead of toxic DMA in peroxide crosslinking of unsaturated polyester resin,improving the work environment and the colour of castings.Examination of cured sample using differential scanning calorimetry showed that resins cured with HMA displayed higher glass transtion temperatures and greater degrees of cure than samples cured using DMA.HMA is more active promoter than DMA owing to the formation of intramolecular hydrogen bond between hydroxide radical and nitrogen atom lead to the poor conjugated of the lone electron pair of nitrogen and π orbit of benzene.Therefore,the electron density of nitrogen is bigger than DMA,the nucleophilicity of promoter HMA is enhanced.更多还原