Study of the miscibility and segmental motion of STMAA–PBMA polymer blends and semi-interpenetrating polymer networks by an ESR spin probe method

✍ Scribed by Furong Qiu; Shiming Chen; Zhenghua Ping

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 148 KB
• Volume: 43
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1556

✦ Synopsis

Linear polymer blends and semi-interpenetrating polymer networks (IPNs) with controlled hydrogen bonding interactions based on poly(styrene-co-methacrylic acid) (STMAA) and poly(butyl methacrylate) (PBMA) were studied by an ESR spin probe method. The observed composite ESR spectra with fast-and slow-motion components in all the samples were ascribed to two-phase morphology. For linear blends, the temperatures T a corresponding to appearance of the fast motion, T d corresponding to the disappearance of slow motion, T 5mT and the rotational correlation times t c increased with increasing carboxylic acid content in STMAA. It was concluded that the degree of mixing of the blends was improved with increasing carboxylic acid content, owing to the enhanced hydrogen bonding interactions between the carboxylic acids in STMAA and the ester groups in PBMA. With respect to semi-IPN samples, there existed a competition in the microphase structure between the intercomponent hydrogen bonding interactions, which improved the miscibility of the samples and the intracomponent cross-linking, which might lead to phase separation in the systems with strong specific interactions. When the semi-IPN contained 29 mol% carboxylic acid, the temperatures T d , T 5mT and t c reached their minimum values, which indicated that the sample reached its maximum miscibility.