Light-Induced Self Organization Phenomena in Polymer Alloys and Its Application to Design Novel Polymer Materials.

本工作的目的是：1)研究二元聚合物共混物在紫外光照射下的自组织过程。2)阐明了利用这一机制设计具有微米级有序结构的新型聚合物材料的可能性。首先对聚苯乙烯/聚2-氯苯乙烯（PS/P2CS）和聚苯乙烯/聚乙烯甲基醚（PS/PVME）共混物进行了时间演化辐照。PS链之间的光交联反应是通过与PS链共价连接的蒽基团的光二聚化引起的。利用相衬光学显微镜、光散射和小角x射线散射研究了辐照强度、辐照时间、退火温度和t跳深对产物形貌的影响。结果表明：在XeF准分子激光或ffg灯照射下，分解过程中产生的浓度波动被有效地冻结。这些结果表明，利用光交联反应，可以设计出在mum范围内具有各种有序结构的多相聚合物材料。-对辐照产生的有序结构的进一步分析表明，PS之间的反应不仅冻结了浓度波动，而且改变了这些结构。当PS/P2CS呈浅t跃时，光散射曲线呈现出多个散射峰，揭示了不同寻常的辐照效应。-分离独立结构对…影响的贡献。在聚苯乙烯/聚丁二烯（PS/PB）的单相区进行了光交联、辐照实验。研究发现，PB链之间的光交联反应导致具有内畴的大调制结构。为了解释这些形态，提出了一个考虑二元聚合物混合物中聚合物链之间非线性反应的反应-扩散模型。另外，激光照射所显示的有序结构的起源还有另一种可能，即由受激蒽的无辐射过程产生的额外热量所引起的对流。实际上，用XeF准分子激光辐照PSA/P2CS共混物得到的形貌表现为典型的瑞利-贝纳德型耗散结构。本文采用计算机模拟方法研究了光照射下聚合物合金的反应扩散图灵不稳定性和瑞利-贝纳德不稳定性之间的竞争关系。少

The Purposes of this work are :1) Investigation of the self organization process in binary Polymer blends irradiated with UV light.2) Elucidation of the possibility for taking advantage of this mechanism to design novel polyner materials with the ordered structures in micrometer range.At first, Polystyrene/poly(2-chlorostyrene)(PS/P2CS)and polystyrene/poly(vinyl methyl ether)(PS/PVME)blends were irradiated during the time evolution of the spinodal decomposition Process. The photo-cross-link reactions between PS chains are induced via the photodimerization of anthracene moieties which are covalently attached to PS chains. The effects of irradiation intensity, irradiation time, annealing temperature and T-jump depths on the resulting morphology were examined by using phase-contrast optical microscope, light scattering and small-angle X-ray scattering.The following results were obtained :- The concentration fluctuations developing during the spinodal decomposition process were efficiently … More frozen upon irradiation with either XeF excimer laser or ffg lamp. These results indicate that by taking advantage of photo-cross-link reactions, multiphase polymer materials with various ordered structures in the mum range can be designed.- Further analysis of the ordered structures resulting from irradiation shows that the reaction between PS does not only freeze the concentration fluctuations but also modify these structures. 'For PS/P2CS submitted to a shallow T-jump, the light scattering profile exhibits multiple scattering peaks, revealing the unusual effects of irradiation.- To separate the contribution of the spinodal structures to the effects of. photo-cross-link, irradiation experiments were performed in the one-phase region of Polystyrene/polybutadiene(PS/PB). It was found that photo-cross-link reactions between PB chains result in the large modulated structures with internal domains- A reaction-diffusion model taking into account of the nonlinear reactions between polymer chains in a binary polymer mixture was proposed in ordered to explain these morphology. Alternatively, there is another possibility for the origin of the ordered structures revealed by irradiation with laser, That is the convection caused by the extra heat originated from the radiationless process of'excited anthracenes. Actually, the morphology obtained by irradiating PSA/P2CS blends with XeF excimer laser shows the typical dissipative structures of the Rayleigh-Benard type.The competition between reaction-diffusion Turing instability and Rayleigh-Benard instability for polymer alloys irradiated with light is currently investigated by computer simulation. Less