Reconsideration on the mechanism of free-radical melt grafting of glycidyl methacrylate on polyolefin
Reconsideration on the mechanism of free-radical melt grafting of glycidyl methacrylate on polyolefin
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DOI：
10.1016/j.polymer.2012.03.035
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发表时间：
2012-05-09
期刊：
影响因子：
4.6
通讯作者：
Xie, Xu-Ming
中科院分区：
文献类型：
--
作者：
Li, Jia-Lin;Xie, Xu-Ming
在Haake混合器上进行了苯乙烯（St）辅助甲基丙烯酸缩水甘油酯（GMA）在聚烯烃上的熔融接枝，并对接枝机理进行了研究。结果表明，在GMA/聚烯烃接枝过程中，GMA存在接枝和解聚的平衡，这一平衡受温度和GMA浓度的影响。研究发现，在加入苯乙烯单体之前，接枝聚甲基丙烯酸甲酯的解聚反应发生在高于聚烯烃上限温度的温度下，并在接枝过程中占主导地位，导致接枝率下降。苯乙烯作为共聚物的加入可以促进平衡向前移动，形成St-GMA链，从而大大提高接枝率。结果表明，将反应温度控制在上限温度以下或改变苯乙烯和GMA的投料顺序都能有效地提高GMA在聚烯烃上的接枝率。(C) 2012 Elsevier Ltd.版权所有。
The styrene (St) assisted melt grafting of glycidyl methacrylate (GMA) on polyolefin was carried out by Haake mixer, and the grafting mechanism was investigated and reconsidered. It was revealed that there is equilibrium of grafting of GMA and depolymerization of grafted PGMA chains in the GMA/polyolefin grafting process, which was affected by both of the temperature and GMA concentration. It was found that the depolymerization of PGMA grafted on polyolefin occurred at the temperature above ceiling temperature of PGMA and dominated the grafting process before the addition of styrene monomer, which induced the decrease in grafting ratio of GMA. Adding styrene as co-monomer could promote the equilibrium moving forward to form the St-GMA chains so that the grafting ratio was greatly improved. It is proved that either controlling the reacting temperature below the ceiling temperature or changing the feeding order of styrene and GMA is effective to attain high grafting ratio of GMA on polyolefin. (C) 2012 Elsevier Ltd. All rights reserved.