Synthesis and Bulk Self-Assembly of Well-Defined Binary Graft Copolymers

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• 作者：Chengmin Hou ; Jiwen Hu ; Guojun Liu ; Jiandong Wang ; Feng Liu ; Heng Hu ; Ganwei Zhang ; Hailiang Zou ; Yuanyuan Tu ; Bing Liao
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：May 28, 2013
• 年：2013
• 卷：46
• 期：10
• 页码：4053-4063
• 全文大小：469K
• 年卷期：v.46,no.10(May 28, 2013)
• ISSN：1520-5835

文摘

Six binary graft copolymers were synthesized, and their graft segregation in bulk was investigated. The copolymers were prepared by a one-pot method involving the quantitative grafting of alkyne-end-functionalized poly(n-butyl acrylate) (PBA-C鈮H) and poly(2-cinnamoyloxyethyl methacrylate) (PCEMA-C鈮H) onto poly(3-azide-2-hydroxypropyl methacrylate) (P(GMA-N₃)) via click chemistry. Of these copolymers, three had a total PBA and PCEMA molar grafting density g of 20%, and their PBA volume fractions V_B among PBA and PCEMA varied between 28% and 57%. V_B was constant at 57%, while g varied between 9.8% and 29.5% for the other three samples. Bulk films were obtained by slowly evaporating the solvent from cast solutions of these copolymers. These films were then annealed above the glass transition temperatures of PBA and PCEMA to facilitate graft segregation. The graft segregation patterns were examined by performing transmission electron microscopy (TEM) analysis of thin sections of these films. The TEM results suggested that the grafted PBA chains formed a disordered wormlike phase in a PCEMA matrix at V_B = 28%. At V_B = 42% and 57%, PBA and PCEMA seemed to form alternating lamellae. In the former case, the PBA layers were thinner than the PCEMA layers, while the PBA layers were thinner in the latter case. All three samples with V_B 57% probably possessed a lamellar morphology. The periodicity of the lamellae increased and the long-range ordering deteriorated as g increased.