Preparation and properties of poly(methyltrifluoropropylsiloxane‐b‐imide) copolymer. I

Abstract

Poly(methyltrifluoropropylsiloxane-block-imide) copolymers (PSBPI), containing various contents of fluorosiloxane, were prepared by the thermal imidization of 3,3Ј,4,4Ј-benzophenonetetracarboxylic dianhydride (BTDA), 4,4Ј-oxydianiline (ODA), and ␣,-aminopropyl-terminated poly(methyltrifluoropropylsiloxane) prepolymer (APMFS). APMFS was prepared from an equilibrium polymerization of (3,3,3-trifluoropropyl)methylcyclotrisiloxane (D 3 Me,CH2,CH2,CF3 ) with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in the presence of the tetramethylammoniumhydroxide (TMAH) catalyst. The content of APMFS, in the reaction mixture, was varied from 0 to 30 wt % of diamine. The structure of copolymer was confirmed by FTIR spectroscopy. The thermal stability, linear coefficient of thermal expansion, modulus, X-ray pattern, and other properties, such as surface enrichment behavior and solubility, were investigated. PSBPI exhibited relatively low crystallinity regardless of the APMFS content in the copolymer. On the other hand, thermogravimetric, thermomechanical, dynamic mechanical, and surface properties were affected by the content of APMFS segment in the copolymer backbone.

Synthesis and characterization of novel fluorosilicone rubber using imide modified vinyl‐containing fluorosilicone resin as cross‐linker

“…In theory, this difference in the polarity and rigidity would lead to the phase seperation between MPA based imide and fluorosilicone polymer, and MPABI‐rich phase would be formed in the fluorosilicone rubber. Actually, the similar microphase separation phenomenon between imide segment and silicone segment had been observed by SEM in poly(methyltrifluoropropylsiloxane‐b‐imide) copolymer …”

“…Actually, the similar microphase separation phenomenon between imide segment and silicone segment had been observed by SEM in poly(methyltrifluoropropylsiloxane-b-imide) copolymer. 19 In this study, SEM was used to study the micro-morphology of the new cross-section of MP-FSR. With the median value of MP-VFS loading, MP-FSR2 was selected as a representative sample while C-FSR2 and P-FSR were chosen as the comparative examples, and the obtained micrographs were showed in Figure 3.…”

“…Polyimide has outstanding comprehensive properties, such as high mechanical strength, excellent thermo-oxidative sta-bility, and solvent resistance. [18][19][20][21][22] And all these properties should be more due to the strong rigidity and polarity of imide heterocycle. Theoretically, grafting imide heterocycle onto flexible fluorosilicone chain, would be a promising approach to increase the mechanical strength.…”

“…23 Considerable efforts have been made for the research of poly(imide-siloxane) copolymer, and more excellent mechanical properties and thermal stability have been obtained. [19][20][21][22] However, all these modifications occur at the backbone of polysiloxane and is very difficult to be maneuvered. No efforts have been found to grafting the imide heterocycle onto the side chain of polysiloxane, which should be a very convenient and promising method, concerning that the synthesis of polysiloxane backbone was based on the most common synthetic route (anionic or cationic ring-opening polymerization of cyclosiloxane).…”

Synthesis and characterization of maleated rosin‐modified fluorosilicone resin and its fluorosilicone rubber

“…Theoretically, grafting imide heterocycle onto flexible fluorosilicone chain would be a promising approach to increase the mechanical strength . Poly(methyltrifluoropropylsiloxane‐block‐imide) copolymers have been prepared by the thermal imidization of carboxylic dianhydride and aminopropyl‐terminated fluorosilicone prepolymer . However, effects of imide on the mechanical strength of fluorosilicone rubber have rarely been reported.…”