Study on the morphology of supramolecular poly(styrene-block-4-vinylpyridine)(3-pentadecylphenol)/ homopolystyrene blends

• Main Authors: Chia-Hao Lee, 李家豪
• Other Authors: Shih-Huang Tung
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/60212992172476306256

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 98 === The blending of block copolymer/homopolymer is a good strategy to improve the properties of polymeric materials. In this thesis, we first studied the binary mixtures of poly(styrene-block-4-vinylpyridine)(PS-b-P4VP) and homopolystyrene(hPS), in which macrophase separation, i.e. the phase separation between hPS and PS-b-P4VP, occurs due to the large difference of molecular weight between hPS and PS-b-P4VP. In addition, the microphase separation between PS and P4VP occurs in the PS-b-P4VP-rich phase and the morphology of microphase separation is controlled by the volume fraction of the PS and P4VP block. We then further incorporated 3-pentadecylphenol(PDP) into the system, which can form hydrogen bonds with the 4VP and transforms PS-b-P4VP into supramolecular PS-b-P4VP(PDP). The supramolecules can self-assemble into hierarchical structure-in-structure morphologies and the morphologies can be tailored by the amount of PDPs. Our research focused on how the amount of PDP affects the morphology of microphase separation in the PS-b-P4VP/hPS blend systems. Spherical microdomains can be obtained at the small amount of PDP. When the amount of PDP is increased, the shape of PS-b-P4VP macrodomains becomes lenslike, in which cylindrical microdomains are packed hexagonally. An unusual U-shape structure, which links two cylinders on the edges of macrodomains, can be observed when the amount of PDP is increased further. In the large excessof PDP, though microdomains remain cylindrical, the regularity of cylinders appear to decrease. In addition, we will discuss how solvents and solvent evaporation rate affect the system. Moreover, we added dodecylbenzene sulfonic acid(DBSA) instead of PDP into PS-b-P4VP/hPS blends and examined the effects of different type of small molecules on the morphology.