| 摘要 |
Non-crystalline elastomeric acetal polymers are disclosed which have ethylenic unsaturation in the polymer backbone. The polymers are synthesized by the ring-opening polymerization of 1,3-dioxolane, 1,3-dioxepane, and the cyclic formal of an ethylenically unsaturated diol having at least 4 adjacent carbon atoms in its main chain. The preferred cyclic formal is 4,7-dihydro-1,3-dioxepin. Because of the ethylenic unsaturation, the elastomeric acetal polymers can be vulcanized or cured with multifunctional vinyl monomers to produce elastomers with improved properties, such as better elasticity, decreased thermoplasticity and decreased solubility. The elastomeric acetals in any of their embodiments are particularly useful for blending with crystalline acetal polymers to improve the impact resistance of the crystalline acetal polymers.
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