Li T, Yu R, Zhao D. Effective Halogen- and Phosphorus-Free Polyphenylene Ether Resin-Based Flame-Retardant Foam.
ACS OMEGA 2021;
6:15246-15256. [PMID:
34151103 PMCID:
PMC8210414 DOI:
10.1021/acsomega.1c01524]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/24/2021] [Indexed: 06/13/2023]
Abstract
A novel halogen- and phosphorus-free intrinsic flame-retardant foam is fabricated from curable phenol-terminated polyphenylene ether resin with a high molecular weight using phenol, formaldehyde, and diphenyl ether as starting materials. The limiting oxygen index (LOI) of the pure foam is 24.90% ± 0.28. When 0.5 wt % silica sol is added, the LOI of the foam (SPF-0.5) is up to 28.5% ± 0.15 and both the combustion heat release rate and total combustion heat are low. Moreover, the SPF-0.5 foam exhibits high carbon residue, high compressive strength, and low pulverization rate and is superior to some previously reported phenolic foam. The flame-retardant mechanism includes the condensed-phase flame retardation and the gas-phase flame retardation, with the former being the main step, which is based on the high cross-linking density, the higher strength and smaller size of foam cells, and the formation of a carbon-silicon compound in the foam. This halogen- and phosphorous-free flame-retardant foam is also environmentally benign.
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