The present invention is directed to cyclic poly(aryl ether) oligomers and mixtures thereof, and methods for the preparation thereof in a highly dilute reaction medium under reaction conditions favorable for ring closure at low degrees of polymerization. These oligomers are represented by the general formula
where each Y is divalent oxygen or divalent sulfur, each Ar is an aromatic diradical which comprises one or more C₆ to C₂₀ arylene groups and has at least one electron withdrawing group attached to an aromatic ring, and n is an integer from 1 to 20 with the proviso that for integer values of n equal to 1 or 2 all linkages between independent aromatic rings comprise at least one atom.
The present invention includes a process for the preparation of poly(aryl ethers) from cyclic poly(aryl ether) oligomers. These low melt viscosity cyclic oligomers undergo ring opening and chain extension upon heating in the presence of a catalyst, forming high molecular weight linear polymers with no coproduct formation. Finished thermoplastic parts and composites may be prepared using this technology with processing techniques normally restricted to thermosetting monomers.
本发明涉及环状聚芳基醚低聚物及其混合物,以及在高度稀释的反应介质中,在有利于低聚合度下闭环的反应条件下制备它们的方法。这些低聚物通式如下
其中,每个 Y 是二价氧或二价
硫,每个 Ar 是芳香族二元环,包括一个或多个 C₆ 至 C₂₀ 芳烯基团,并至少有一个取电子基团连接到芳香环上,n 是 1 至 20 的整数,但 n 的整数值等于 1 或 2 时,独立芳香环之间的所有连接至少包括一个原子。
本发明包括一种从环状聚芳基醚低聚物制备聚芳基醚的工艺。这些低熔融粘度的环状低聚物在催化剂存在下加热时会发生开环和链延伸,形成高分子量的线性聚合物,且不会产生副产品。使用这种技术可以制备热塑性塑料零件和复合材料成品,其加工技术通常仅限于热固性单体。