聚醚硫■與熱向性液晶聚酯團聯共聚合物之合成

Abstract

本研究目的是以縮合聚合方法讓含官能基之聚醚硫■與不同液晶單體進行 共聚合,合成兩系列團聯共聚合物,以探討其做為分子複合材料之可能性。 本研究首先以過量雙酚-A和二氯苯基硫■合成出含■基於兩端之聚醚硫 ■,將所合成之聚醚硫■和對■基苯甲酸及2-■基-6-■甲酸在■啶溶液中 進行共聚合反應,合成出第一系列之團聯共聚合物。結果顯示,聚醚硫■和 液晶單體以餵入等重量比來進行共聚合有最佳之聚合效果。所有團聯共聚 合物顯現出兩個玻璃轉移溫度,第一個玻璃轉移溫度出現在74.5.degree .C.sim.76.5.degree.C間,是屬於液晶鏈段的分子行為,第二個玻璃轉移溫 度出現在128.8.degree.C.sim.140.8.degree.C間,是屬於聚醚硫■鏈段的 分子行為。玻璃轉移溫度受所接液晶鏈段長短及聚醚硫■鏈段因素影響, 並無明顯規則性,而熔點則隨黏度增加(亦即是液晶鏈段長度增加)而往高 溫偏移,其溫度出現在248.0.degree.C.sim.259.8.degree.C間。所有樣品 在偏光顯微鏡下均可看到向列型液晶紋理圖。將聚醚硫■和4,4'- dicarboxy-.alpha.,.omega.-diphenoxylalkane及聯苯酚在■啶溶液中進 行共聚合反應,合成出第二系列之團聯共聚合物。在液晶單體中導入柔軟 間距使共聚合物溶解性增加及熔解溫度降低。結果顯示,所有的液晶共聚 合物皆呈現一個玻璃轉移溫度和一個熔點,由於分子量等因素影響而使玻 璃轉移溫度和熔點與柔軟間距碳數間無明顯規則性 ,其玻璃轉移溫度出現 在136.0.degree.C.sim.169.6.degree.C間,熔點出現在254.9.degree.C. sim.316.0.degree.C間。於偏光顯微鏡下觀察,此系列共聚合物亦均呈現 向列型液晶相。 The goal of this study is to present the synthesis and characterization of two series of block copolymers made from polycondensation of telechelic polyether sulfone(PSF-2OH) and liquid crystalline monomers for the application of the molecular composite.The polyether sulfone telechelic was prepared by condensation of excess bisphenol-A and 4,4'-dichlorodiphenyl sulfone in DMSO. The synthesized PSF-2OH was allowed to copolymerized with a mixture of 4-hydroxybenzoic acid(HBA) and 2-hydroxy-6-naphtholic acid(HNA) with different feeding weight ratios to from the first series of block copolymers.The results reveal that a better co- polymer is obtained when the feeding weight ratios of PSF-2OH and liquid crystalline monomers are equal.All of the block co- polymers reveal two glass transitions.The first glass transition which belong to the molecular motion of LC blocks,present at the temperature range from 74.5 .degree.C to 76.5 .degree.C. The second glass transitions which belong to the molecular motion of PSF blocks prepent at the temperature range from 129.8.degree .C to 140.8.degee.C.The glass transition temperatures do not show any trend due to the difference in the length of LC block and the weight percentage of PSF block.The melting temperatures of block copolymers increase which increasing the intrinsic viscosity,i.e. the length of LC block. Optical microscopic observation reveals that all of the block copolymers show nematic liquid crystalline behavior.