摘要
采用绝热量热法研究共聚合动力学 ,在Dewar聚合釜中以 2 ,2′ -偶氮二异庚腈为引发剂进行苯乙烯和甲基丙烯酸甲酯在甲苯溶液中的绝热共聚合试验 ,分别用末端模型与Fuuda和Inagaki的前末端模型拟合交叉链增长焓 .结果表明 ,用末端模型拟合的交叉链增长焓之和 (-ΔHR12 ) + (-ΔHR2 1)与文献值吻合 ,而用Fukuda和Inagaki的前末端模型拟合的数值则远小于文献值 ,且 -ΔHR12 的绝对值远远小于 -ΔHR2 1,这意味着该模型在模拟本系统时存在问题 。
The adiabatic calorimetry is a very simple and precise means to measure the rate of polymerization. This method was used to acquire the temperature-time curves of the copolymerization of styrene (St) and methyl methacrylate (MMA) in toluene initiated by 2,2-azobis (2, 4-dimethylvaleronitrile). The sums of crossed chain propagation enthalpy (-δ HR12) + (-δ HR12) were simulated based on terminal model and penultimate model of Fukuda and Inagaki. The reactor was a 1.5 litre Dewar-reactor equipped with temperature sensors (Pt-100) and a computer, the surrounding temperatures can be recorded and calculated on line. At 70-90° C and in the atmosphere of helium, St and MMA were copolymerized and a series of temperature-time curves were obtained by varying the initial concentrations of initiator from 0.02 to 0.03 mol· L-1, and mole concentration ratio of St to MMA ranging from 2/8 to 8/2. The sums of crossed chain propagation enthalpy (-δ HR12) + (-δ HR21) were simulated as 151.03 kJ · mol-1 and 76.57 kJ·mol-1 respectively based on the terminal model and penultimate model of Fukuda and Inagaki. The results show that the value simulated based on the terminal model is coincident with the published datum (136.95 kJ· mol-1), but the value simulated according to penultimate model of Fukuda and Inagaki is much less than the published one. Besides, the great difference between (δ HR12) and (-δ HR21) in the penultimate model of Fukuda and Inagaki implies that there remain some problems to be studied further. However, it is still insufficient to prove that the terminal model is better than the penultimate model of Fukuda and Inagaki for simulating the copolymerization system.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2001年第2期119-124,共6页
CIESC Journal
