Effect of side groups on the properties of silicon‐containing arylacetylene resins

Abstract

Four silicon-containing arylacetylene resins were synthesized by polycondensation of Grignard reagent of m-diethynylbenzene with methylethyldichlorosilane, dimethyldichlorosilane, methylphenyldichlorosilane, and diphenyldichlorosilane, respectively. The structures of the resins were verified by nuclear magnetic resonance spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The solubility, crystallinity, and rheological character of the resins were characterized.The curing behavior was traced by differential scanning calorimetry (DSC) and FTIR analyses. The effect of the side groups on the silicon atom on the properties was investigated. The results show that the resins with asymmetrical side groups display better processability (wide processing window) as compared with those with symmetrical side groups. The resin with side phenyl groups shows higher flexural strength but lower thermal stability as compared with those without side phenyl groups. Meanwhile, the side phenyl groups also enhance the temperature at which secondary relaxation occurs.

Effect of the linking positions on the benzene ring on properties of poly(silane arylether arylacetylene)s

“…As shown in Figure 2A, there exist two broad exothermic peaks for the PSEA resins. The strong exothermic peak in the range of 150 ~ 300 °C is due to the crosslinking reactions of alkynyl groups while heating 12 . And the relatively inert internal alkynyls continue to react at higher temperature, leading to an exothermic peak from 310 °C to 380 °C 1,3,28,29,35 .…”

“…The strong exothermic peak in the range of 150 $ 300 C is due to the crosslinking reactions of alkynyl groups while heating. 12 And the relatively inert internal alkynyls continue to react at higher temperature, leading to an exothermic peak from 310 C to 380 C. 1,3,28,29,35 Specifically, the exothermic peaks in high-temperature region for pmp-PSEA and pop-PSEA resins are stronger due to the irregular structures. There is a tiny elevation in T p from ppp-PSEA to pmp-PSEA followed by pop-PSEA, indicating that the alkynyl reactivity slightly drops in order.…”

“…One effective method for the improvement of solubility and processability is to adjust structural regularity by incorporating geometrically asymmetric units. The use of asymmetric disubstituted dichlorosilanes, such as dichloromethylphenylsilane, accomplished the purpose to a limited extent 10–12 . But to our knowledge, there have been no reports about PSEA resins derived from geometrically asymmetric arylacetylene monomers to date.…”

“…The use of asymmetric disubstituted dichlorosilanes, such as dichloromethylphenylsilane, accomplished the purpose to a limited extent. [10][11][12] But to our knowledge, there have been no reports about PSEA resins derived from geometrically asymmetric arylacetylene monomers to date.…”

A new poly(trialkylsilylethynylphenylacetylene)s membrane toward enhanced oxygen permeability

“…Poly(silylene arylacetylene) (PSA) is an oligomer with the ethynylene-arylene-ethynylene-silylene structure as a repeating unit, showing excellent heat resistance after crosslinking. 30 Currently, the suitable structure of most poly(substituted acetylene)s membranes studied for O 2 /N 2 separation is that of silyl directly attached to a benzene ring, 31 for example, poly(o,p-bis(trimethylsilyl)phenylacetylene) (poly(o,p-BSPA)), poly(o-trimethylsilylphenylacetylene) (poly (o-SPA)), and poly(p-trimethylsilylphenylacetylene) (poly (p-SPA)) (their structures are shown in the Data S1). In this article, we designed and synthesized a new series of poly(substituted acetylene)s with the insertion of an acetylene group between the benzene ring and the silyl group named as poly(trialkyl silylethynylphenylacetylene)s and abbreviated as PSEPAs.…”