Mixing Thermodynamics of Ternary Block鈥揜andom Copolymers Containing a Polyethylene Block

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• 作者：Bryan S. Beckingham ; Adam B. Burns ; Richard A. Register
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：April 9, 2013
• 年：2013
• 卷：46
• 期：7
• 页码：2760-2766
• 全文大小：352K
• 年卷期：v.46,no.7(April 9, 2013)
• ISSN：1520-5835

文摘

The mixing interactions among polyolefins and other hydrocarbon polymers are of strong fundamental and practical interest, especially in mixtures involving the simplest member of the family, polyethylene (E). The present work examines the interaction energy densities between E and random copolymers of styrene and hydrogenated isoprene (SrhI), and between E and random copolymers of vinylcyclohexane and hydrogenated isoprene (VCHrhI), by measuring the order鈥揹isorder transition temperatures of near-symmetric E鈥揝rhI and E鈥揤CHrhI diblock鈥搑andom copolymers. The E鈥揝rhI case is of special interest, since the solubility parameters 未 fall in the order 未_S > 未_E > 未_hI; if regular mixing were obeyed, zero interaction energy between E and SrhI could be obtained for a suitable SrhI composition. However, large positive deviations from regular mixing are observed in the E鈥揝rhI system, while smaller but significant negative deviations are observed in the E鈥揤CHrhI system. Notwithstanding these irregularities, a ternary mixing model (鈥渃opolymer equation鈥?, using independently determined values of the three component interaction energy densities, provides a good representation (within 鈮?5%) of the experimental interaction energies.