四官能度过氧化物引发苯乙烯本体聚合动力学

Kinetics of Bulk Free Radical Polymerization of Styrene Initiated by Tetrafunctional Initiator

用四官能度过氧化物引发剂聚醚聚过氧化碳酸叔丁酯(JWEB50)引发苯乙烯(St)本体聚合,采用膨胀计测微观动力学法,研究了聚合温度、过氧键浓度对JWEB50引发St本体聚合速率的影响。结果表明,温度升高10℃,聚合速率增大到原来的2～2 5倍;聚合速率与过氧键浓度的1/2次方成正比,为偶合终止。与单官能度引发剂过氧化2-乙基己基碳酸叔丁酯(TBEC)做空白对照,比较了两种过氧化物引发St本体聚合动力学,发现在相同温度、过氧键浓度下,二者的动力学曲线重合。用差示扫描量热仪(DSC)对JWEB50引发得到的聚苯乙烯(PS)进行热分析,发现不同转化率下得到的PS中均含未分解的过氧键,且过氧键的分解温度均在170℃左右。

Polyether poly-t-butylperoxy carbonate （JWEBS0） was used to initiate bulk free radical polymerization of styrene （St）. The effects of the polymerization temperature and concentration of [O-O] on the polymerization rate of St with JWEB50 were discussed through the dilatometers method. The polymerization rate would increase 2-2.5 times when the polymerization temperature increases 10℃. And it is proportional to the square of the concentration of [O-O]. The existence of the [O-O] in polystyrene （PS） molecular prepared with JWEB50 was determined by differential scanning calorimeter （DSC）. [O-O] in the PS molecular which were obtained at different monomer conversions decomposed at the same temperature about 170 ℃. And the concentration of [O-O] in PS molecular decreased with the monomer conversion. Compared to its monofunctional counterpart tert-butyl （2-ethylhexyl） monoperoxycarbonate （TBEC）, it showed that the kinetic curves of polymerization with JWEBS0 and TBEC overlapped at equal molar concentrations of [O-O].