Relaxation behavior of random copolymers containing rigid fumarate and flexible acrylate segments by dynamic mechanical analysis

Autor: Yasuhito Suzuki, Akikazu Matsumoto, Kenji Funamoto, Tomoya Tsujimura
Rok vydání: 2019
Předmět:
Zdroj: Polymer Journal. 51:1163-1172
ISSN: 1349-0540
0032-3896
DOI: 10.1038/s41428-019-0226-z
Popis: Due to the absence of a methylene spacer in the main chain, poly(substituted methylene)s with rigid structures possess some distinguished properties including a unique β-relaxation process. In this study, two series of random copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) and n-butyl acrylate (nBA) with various compositions were synthesized. The relaxation behavior of the copolymers was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The α-relaxation temperature of the copolymers decreased as the acrylate content increased. Depending on the glass transition temperature (Tg) of the counterpart copolymers, that is, Tg = 156 °C for the homopolymer of AdA and Tg = –53 °C for the homopolymer of nBA, the β-relaxation temperature from the DiPF segments systematically shifted. While the β-relaxation temperature increased when copolymerized with AdA, the temperature decreased when copolymerized with nBA. Both copolymers maintained a high storage modulus of more than 10 MPa in the range between the α- and β-relaxation temperatures. The merging of the α and β processes at an intermediate composition was also observed. The random copolymerization of DiPF and acrylates enables us to fine tune the properties associated with the β-relaxation of DiPF segments. The relaxation behavior of random copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) and n-butyl acrylate with various compositions was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The β relaxation temperature systematically shifted depending on the glass transition temperature of the counterpart copolymers, and the merging of the α and β processes at an intermediate composition was also observed. Thus, the random copolymerization of DiPF and acrylates enables us to fine tune the properties associated with the β relaxation of DiPF segments.
Databáze: OpenAIRE
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