Exploration on structural rules of highly efficient flame retardant unsaturated polyester resins.
J Colloid Interface Sci
; 608(Pt 1): 142-157, 2022 Feb 15.
Article
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| MEDLINE
| ID: mdl-34624762
ABSTRACT
Owing to the lack of research on structure-activity relationship and interaction mechanism between unsaturated polyester resins (UPR) and flame retardants, it has been a big challenge to prepare high-efficiency flame retardants for UPR in industry. In this research, to explore structural rules of high-efficiency flame retardants, several polymeric flame retardants were synthesized with varied main-chain, side-chain, phosphorus valence states and contents of flame retardant elements. The thermal stabilities of flame retardants and UPR composites were firstly assessed. It has been found the interaction existed between flame retardants and UPR, through transesterification reaction and ß scission pathway in polyester and polystyrene chains. With only 15â¯wt% of PCH3-S, UPR composites can reach V0 rating in UL-94. The PHRR and THR values can be maximumly decreased by 71.66 % and 77.67 %, with 20â¯wt% of PB-S. It has been found flame retardants with sulfone group andâ¯+â¯3 valence state of phosphorus in molecular backbone can release SO2 and phosphorus containing compounds in gaseous phase, which diluted fuel fragments and catalyzed Hâ
and HOâ
radical removal. The mechanism for improved flame retardancy of UPR composites with various polymeric flame retardants were discussed in detail. Some general rules for highly efficient flame retardant UPR can be summarized First, gaseous phase flame retardant mechanism plays the major role in improvement of flame retardant performance of UPR composites; Second, the combination ofâ¯+â¯3 valence state of phosphorus structures, higher phosphorus contents and sulfone groups effectively improves the flame retardant efficiency of flame retardants.
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MEDLINE
Asunto principal:
Retardadores de Llama
Idioma:
En
Revista:
J Colloid Interface Sci
Año:
2022
Tipo del documento:
Article