Preparation method of self-crosslinked phosphazene elastomer

Abstract

The invention discloses a preparation method of a self-crosslinked phosphazene elastomer. Crosslinking of the polyphosphazene is realized via heating, adding of cross-linking agent is not needed, and mechanical properties and thermal properties of an obtained crosslinked product are excellent. According to the preparation method, a substituent group with terminal hydroxyl groups is mixed with alkoxy, phenoxyl, and the like so as to take the place of polydichlorophosphazene, the phosphazene elastomer capable of realizing crosslinking is obtained, and dehydration reaction of crosslinking points is realized via heating and drying so as to form crosslink bonds. When the phosphazene elastomer is dried at 100 DEG C for 24h, self-crosslinking can be realized, and mechanical properties of the linear phosphazene elastomer are improved greatly, product thermal stability is improved, and the initial thermal decomposition temperature can be increased by 30 to 50 DEG C. The phosphazene elastomer is capable of realizing crosslinking in drying processes, and the crosslinking method of the phosphazene elastomer is simple, so that crosslinking difficulty and crosslinking cost of linear substituted polyphosphazene are reduced greatly, and the preparation method possesses significant importance on scale production of phosphazene derivative elastomer materials.

Description

technical field [0001] The invention prepares a polyphosphazene with self-crosslinking characteristics. The polyphosphazene can be crosslinked by heating and increasing the temperature without adding a crosslinking agent, and the crosslinked product has excellent mechanical properties and thermal properties. Background technique [0002] Linear polyphosphazene derivatives are outstanding in multifunctional and high-performance polymer materials due to their stable main chain structure and variable side group types. As a polyphosphazene elastomer, it usually needs to have enough molecular chain cross-linking to show good stretch, resilience and corresponding mechanical strength behavior. Linear polydichlorophosphazene is an indispensable intermediate for the synthesis of linear polyphosphazene derivatives. The polyphosphazene derivatives prepared by the side group substitution reaction of linear polydichlorophosphazene are relatively sticky and soft elastic materials. It can...

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Problems solved by technology

For example, H.R.Allcock et al introduced a small amount of 2-butenyloxy, (4-(allyloxy)phenyl)phenoxy, etc. The substituent of the double bond is cross-linked by ultraviolet light to obtain a cross-linked polyphosphazene elastomer. These methods have better cross-linking effects, but need to add cross-linking agents or more complicated cross-linking conditions

[0004] There are many defects in the traditional polyphosphazene elastomer cross-linking method: although the method of initiating cross-linking with an external cross-linking agent is more efficient, the thermal stability of the cross-linking agent usually used is insufficient, which will affect the thermal stability of the cross-linked phosphazene elastomer product. Stability; the method of light-induced crosslinking ensures the thermal stability of the product, but conditions such as ultraviolet light make the production cost higher

[0005] In the existing polyphosphazene cross-linking methods, there have been reports on the use of terminal hydroxyl groups to form cross-linking bonds, but cross-linking agents have been used in the reports, and there have been no reports of self-crosslinking of terminal hydroxyl groups to prepare cross-linked polyphosphazene elastomers. to report

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