Rapid Modular Synthesis and Processing of Thiol鈥揈ne Functionalized Styrene鈥揃utadiene Block Copolymers

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• 作者：Joshua S. Silverstein ; Brendan J. Casey ; Mary E. Natoli ; Benita J. Dair ; Peter Kofinas
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：April 10, 2012
• 年：2012
• 卷：45
• 期：7
• 页码：3161-3167
• 全文大小：314K
• 年卷期：v.45,no.7(April 10, 2012)
• ISSN：1520-5835

文摘

Diblock and triblock copolymers of poly(styrene)-block-poly(1,2-butadiene) (PS/PB) and PS/PB/PS were modified by photochemical thiol鈥揺ne chemistry to process selected functional nanopatterned polymers, with reaction completion in 1 h. PB molecular weight (MW) and thiol鈥揺ne ratios were systematically varied based on a model monomer, boc-cysteamine, to determine the efficiency of the reaction. The results demonstrate the polydispersity index (PDI) of modified block copolymers significantly increased when low thiol鈥揺ne ratios were employed and sometimes induced gelation of the reacted polymers. Using a 10-fold excess of thiol, functionalizations between 60% and 90% were obtained for amines, carboxylic acids, amides, and a pharmaceutical with a pendant thiol. Differential scanning calorimetry showed a 30鈥?0 掳C increase in the glass transition temperature of the daughter polymers. Subsequently, these polymers were spin-coated from solvents found suitable to form self-assembled block copolymer films. The microstructure domain spacing for each polymer was consistent with those originating from the parent polymer. This technique described allows for the formation of nanopatterned block copolymer films with controlled chemistries from a single source material.