Synthesis and thermally stimulated current study of molecular relaxations of the grafted polymethylphenylsiloxane segment in thiodiphenol-modified epoxy resin
✍ Scribed by Tun-Yuan Lo; Steve K. Huang
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 196 KB
- Volume
- 69
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
A series of grafted polymethylphenylsiloxane (PMPS) segments in thiodiphenyl-containing epoxy resin (ESTP) was prepared. The structure was evaluated by IR, 1 H-NMR, and 13 C-NMR measurements. DSC measurements on the grafted ESTP epoxy resins showed a decreasing trend for T g with increasing content of PMPS siloxane. The TSC measurements further confirmed this trend. This result suggests that the matrix of ESTP copolymer was less rigid with grafting of PMPS oligomer, due to the Si{O{C linkage at the opened glycidyl ether chain located approximately between the BPA and 4,4 -thiodiphenoxyl chains in the epoxy backbone. A new and broad sub-T g transition appeared at 060ЊC in the TSC spectrum was observed for the cooperative motion of this siloxane moiety. All copolymers showed sub-T g relaxations of gand dmodes, observed at 0100 and 0130ЊC, respectively. These two relaxations may be attributed to the motions of BPA and the terminal groups in the epoxy matrix. ᭧ 1998