POLYCARBONATE SAN COPOLYMER INTERACTION
POLYCARBONATE SAN COPOLYMER INTERACTION
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DOI：
10.1016/0032-3861(93)90503-3
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发表时间：
1993-01-01
期刊：
影响因子：
4.6
通讯作者：
PADWA, AR
中科院分区：
文献类型：
--
作者：
CALLAGHAN, TA;TAKAKUWA, K;PADWA, AR
聚碳酸酯 (PC) 与 ABS（丙烯腈-丁二烯-苯乙烯）材料的共混物具有商业上有用的特性，无需增容剂，而增容剂对于大多数其他商业多相共混物来说是必需的。有人提出，这是由于 PC 和 ABS 苯乙烯-丙烯腈 (SAN) 共聚物基体之间有利的热力学相互作用。各种证据表明，这种相互作用在丙烯腈含量约为 25 wt% 时最佳，这大致是共沸物和大多数商业材料的组成。本文介绍了 PC-SAN 共混物相行为的临界分子量分析，从而得出与现有事实一致的相互作用能的定量估计。当 PC 和 SAN 组分的分子量分别降低至约 3000 时，它们的共混物变得可混溶，并且观察到的相行为允许使用 Flory-Huggins 和 Sanchez-Lacombe 状态方程理论根据二元相互作用模型计算相互作用能。必要时考虑端基效应。估计的相互作用能是基于共聚碳酸酯和 SAN 共聚物共混物的相行为的先前估计的改进。目前的估计可以预测界面张力，这与此处和其他地方介绍的 PC-SAN 共混物的形态观察结果一致。它还预测，部分混溶的程度非常有限，并且当混合时，应该会产生非常小的组分玻璃化转变，正如本文和其他人对纯化 SAN 材料所观察到的那样。先前的相反主张是由于商业SAN共聚物中低聚物相之间的分配而产生的。
Blends of polycarbonate (PC) with ABS (acrylonitrile-butadiene-styrene) materials have commercially useful properties without requiring a compatibilizer, which is necessary for most other commercial multiphase blends. It has been proposed that this is due to a favourable thermodynamic interaction between PC and the styrene-acrylonitrile (SAN) copolymer matrix of ABS. A variety of evidence suggests this interaction is optimum at about 25 wt% acrylonitrile, which is roughly the composition of the azeotrope and of most commercial materials. A critical molecular weight analysis of the phase behaviour of PC-SAN blends is presented here, which leads to a quantitative estimate of the interaction energy that is consistent with available facts. When the molecular weights of the PC and SAN components are reduced to about 3000 each, their blends become miscible and the observed phase behaviour allows calculation of interaction energies in terms of a binary interaction model using both the Flory-Huggins and the Sanchez-Lacombe equation of state theories. End-group effects were accounted for as necessary. The estimated interaction energy is a refinement of a previous estimate based on the phase behaviour of copolycarbonates and SAN copolymer blends. The current estimate allows prediction of interfacial tensions that are consistent with morphology observations for PC-SAN blends presented here and elsewhere. It also predicts that the extent of partial miscibility is very limited and should produce very small shifts in the glass transitions of the components when blended as observed here and by others for purified SAN materials. Prior claims to the contrary result from partitioning between the phases of oligomers in commercial SAN copolymers.