STUDY OF MICROPHASE SEPARATION IN BLOCK CO-POLYMERS OF STYRENE AND ALPHA-METHYLSTYRENE IN THE GLASS-TRANSITION REGION USING QUANTITATIVE THERMAL-ANALYSIS
STUDY OF MICROPHASE SEPARATION IN BLOCK CO-POLYMERS OF STYRENE AND ALPHA-METHYLSTYRENE IN THE GLASS-TRANSITION REGION USING QUANTITATIVE THERMAL-ANALYSIS
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DOI：
10.1021/ma60078a048
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发表时间：
1980-01-01
期刊：
影响因子：
5.5
通讯作者：
WUNDERLICH, B
中科院分区：
文献类型：
--
作者：
GAUR, U;WUNDERLICH, B
测定了聚α-甲基苯乙烯和三种微相分离的高相对分子质量嵌段共聚物--S-S和S-MS的热容。还测量了直径为85-868 nm的聚苯乙烯微球(温度范围为310-490K)的热容。这些数据与我们数据库中新建立的聚苯乙烯和聚α-甲基苯乙烯的热容进行了比较。嵌段共聚物有两个玻璃化转变。MS嵌段玻璃化转变的起始温度比均聚物低43K，而S嵌段玻璃化转变的终点温度比均聚物高31K，但玻璃化转变温度变化不大。聚苯乙烯球体也显示出玻璃化转变开始的降低。所有的影响都与微相的比表面积有关。在这些嵌段共聚物中，玻璃化转变时的滞后热容被降低。
Heat capacities of poly (a-methylstyrene) and three microphase-separated, high molecular weight block copolymers of a-methylstyrene (MS) and styrene (S) of the type MS-S and MS-S-MS have been measured. Also measured were heat capacities of polystyrene spheres of 85-868-nm diameter (temperature range 310-490 K). The data are compared to newly established heat capacities of polystyreneand poly (a-methylstyrene) from our data bank. The block copolymers have two glass transitions. The MS-block glass transition has its beginning up to 43 K lower than the homopolymer, while the S-block glass transition has its end up to 31 K higher than the homopolymer, but there is little change in the glass transition temperature proper. Polystyrene spheres show also a lowering of the beginning of the glass transition. All effects are related to the specific surface area of the microphases. Hysteresisin heat capacity at the glass transition is diminished in these block copolymers.