COMBINED TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROMETRY AND X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF THE SURFACE SEGREGATION OF POLY(METHYL METHACRYLATE) (PMMA) IN BISPHENOL-A POLYCARBONATE PMMA BLENDS
COMBINED TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROMETRY AND X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF THE SURFACE SEGREGATION OF POLY(METHYL METHACRYLATE) (PMMA) IN BISPHENOL-A POLYCARBONATE PMMA BLENDS
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DOI：
10.1021/ma00117a038
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发表时间：
1995-06-19
期刊：
影响因子：
5.5
通讯作者：
DEWEZ, JL
中科院分区：
文献类型：
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作者：
LHOEST, JB;BERTRAND, P;DEWEZ, JL
采用x射线光电子能谱（XPS）和飞行时间二次离子质谱（ToF SIMS）研究了双酚A聚碳酸酯（PC）和聚甲基丙烯酸甲酯（PMMA）共混物表面的相偏析。以二氯甲烷(CH（2)CL(2)）为互溶剂，将不同组分的共混物溶液浇铸在硅片上。在共混物表面观察到明显的PMMA偏析。事实上，XPS数据的定量分析表明，PMMA表面摩尔浓度首先随着PMMA体积浓度的增加而急剧增加（体积浓度为2.5%时，表面浓度达到PMMA的70%），然后继续缓慢增加，并在体积浓度为38.8%时达到饱和。ToF SIMS结果表明，即使在高PMMA表面浓度下，PC仍然存在。半定量的ToF SIMS分析也与XPS结果相关联，证实了在每种聚合物表面浓度相当的情况下，即使存在基体效应，也存在分离现象。两种聚合物表面张力的差异可以解释这种偏析现象。表面形态也通过ToF SIMS成像模式进行采样，但没有检测到对比度，尽管光学图像显示了体中的两相系统。
Phase segregation at the surface of Bisphenol A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) blends is studied by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF SIMS). Blends with different compositions were solution-casted onto silicon wafers with dichloromethane (CH(2)CL(2)) as the mutual solvent. A sharp PMMA segregation is observed at the surface of the blends. In fact, the quantitative analysis of the XPS data shows that the PMMA surface molar concentration increases first steeply with the PMMA bulk concentration (the surface concentration reaches 70% of PMMA for a 2.5% bulk concentration), and then it continues to increase slowly and saturates for a 38.8% hulk concentration. The ToF SIMS results show that PC remains detected even for high PMMA surface concentration. A semiquantitative ToF SIMS analysis is also presented, which correlated with the XPS results and confirmed the segregation even if matrix effects are detected when the surface concentration of each polymer is comparable. The segregation is explained by the difference of surface tension between the two polymers. The surface morphology is also sampled by the ToF SIMS imaging mode, but no contrast is detected although optical images reveal a two-phase system in the bulk.