Thermal and mechanical properties of random copolymers of diisopropyl fumarate with 1‐adamantyl and bornyl acrylates with high glass transition temperatures

Abstract

We report the thermal, optical, and mechanical properties of random copolymers produced by radical copolymerizations of diisopropyl fumarate (DiPF) with 1‐adamantyl acrylate (AdA) and bornyl acrylate (BoA). The effects of a methylene spacer included in the main chain and bulky ester alkyl groups in the side chain on the copolymer properties are discussed. The produced copolymers are characterized by NMR and UV–vis spectroscopies, size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis (DMA). The copolymerization rate and the molecular weight of the copolymers increase with an increase in the acrylate content in feed during the copolymerization (Mw = 25–110 × 103). The onset temperature of decomposition (Td5) and the glass transition temperature (Tg) of the copolymers also increase according to the content of the acrylate units (Td5 = 296–329 °C and 281–322 °C, Tg = 80–133 °C and 91–106 °C for the copolymers of DiPF with AdA and BoA, respectively). Transparent and flexible copolymer films are obtained by a casting method and their optical properties such as transparency and refractive indices are investigated (nD = 1.478–1.479). The viscoelastic data of the copolymers are collected by DMA measurements under temperature control. The storage modulus decreases at a temperature region over the Tg value of the copolymers, depending on the structure and amount of the acrylate units. The sequence structure of the copolymers is analyzed based on monomer reactivity ratios and composition in order to discuss the copolymer properties related to chain rigidity and sequence length distribution. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 288–296

Facile synthesis of graft copolymers containing rigid poly(dialkyl fumarate) branches by macromonomer method

“…PDiPF is reported to show α‐relaxation, that is, T g , at about 260 °C, where decomposition of PDiPF also proceeds . Several literatures reported the temperatures of β‐transition determined by DSC, and the values range from 62 to 74 °C . The currently observed β‐relaxation (54 °C) is slightly lower than those reported in the literatures.…”

“…3,[8][9][10][11] Dialkyl fumarates are 1,2-disubstituted vinyl monomers and undergo radical high polymerization to generate poly(substituted methylene)s, which do not contain a rotatable methylene group in the main chain and show rigid nature as a polymer obtained from vinyl monomers. Poly(dialkyl fumarate)s possess high transparency, 12 good gas permeability, 13 and high thermal stability, 14 and are useful industrial polymeric materials. To modify poly(dialkyl fumarate)s with maintaining their poly(substituted methylene) structure, graft and block copolymers containing a poly(dialkyl fumarate) chain are required.…”

Synthesis of transparent block copolymers consisting of poly(diisopropyl fumarate) and poly(2‐ethylhexyl acrylate) segments by reversible addition‐fragmentation chain transfer polymerization using trithiocarbonates as the chain transfer agents

“…In the DSC thermograms of the block copolymers, no transition due to the α‐transition of the PDiPF segment, that is, the T g for PDiPF, was not observed. Previously, it was pointed out that PDiPF with a rigid chain structure did not show a clear T g transition below the onset temperature of decomposition . The T g due to the P2EHA segment was observed at −71 °C for the block copolymer with a higher P2EHA content (Table ).…”

“…In the present study, we further demonstrated that trithiocarbonate compounds are also useful for the well‐controlled RAFT polymerization of DiPF and the synthesis of the AB and ABA block copolymers. The DiPF chain has a unique characteristic as the nonflexible polymer because of the steric bulkiness of the isopropoxycarbonyl group as the side groups on each carbon of the main chain . We are now continuing the investigation of the mechanical properties as well as the detailed optical properties of polymers containing rigid polyfumarate segments and the results will be reported in the future.…”

“…High‐temperature and transparent polymer materials have become important for information and electronics applications, such as coating, disk, fiber, display, electronic devices, solar cells, and so on . The radical polymerization of dialkyl fumarates provides rigid poly(substituted methylene)s as some of the transparent acrylic polymers . Recently, we reported the reversible addition‐fragmentation chain transfer (RAFT) polymerization of diisopropyl fumarate (DiPF) as the most suitable method for the controlled polymerizations of the fumarates by living radical polymerization techniques .…”