Two-component initiator systems for the ring-opening polymerization of oligomeric cyclic bisphenol-A carbonates: The in situ cleavage of disulfides by triarlyphosphines
✍ Scribed by Herman O. Krabbenhoft; Daniel J. Brunelle; Eric J. Pearce
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 98 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
A two-component initiator system based on the in situ cleavage of phenyl disulfide by a triarylphosphine has been developed for the ring-opening polymerization of cyclic bisphenol-A (BPA) carbonate oligomers. This development has potential use in composite applications such that the prepolymer can suitably wet the composite material before being converted to high-molecular-weight polymer. The initiator precursors (phenyl disulfide and triphenylphosphine) do not independently initiate significant ring-opening polymerization of the oligomeric cyclic BPA carbonate mixture. A mixture of cyclic BPA carbonate oligomers and one of the initiator components (phenyl disulfide), combined and heated at 300ЊC with a mixture of the cyclics and the other initiator component (triphenylphosphine), does produce a high-molecular-weight polymer ( M w Å Ç 70,000). The polymerization-initiating species is thought to be thiophenyltriphenylphosphonium thiophenoxide. The effects of concentration of the initiator components, reaction temperature, time, and so forth on polymerization were studied; in general, the degree of polymerization ranged from about 65 to 75%.