Phosphorus and Silicon Containing Low‐Melting Organic–Inorganic Glasses Improve Flame Retardancy of Epoxy/Clay Composites

Abstract

New low‐melting organic–inorganic glassy polymers containing phosphorus and silicon are synthesized by the reaction between phenylphosphonic acid and methyltrichlorosilane or methyltriethoxysilane. They possess both low‐softening points and high onset decomposition temperatures, which are favorable for preparing flame retardant composites. Although the glass by itself is sensitive to water, the composites are not significantly affected in that way. For glass/clay/epoxy composites glass transition temperature (Tg) as well as storage modulus increase with the glass amount. The glasses improve flame retardancy significantly due to flame inhibition and the formation of fire residue working as protection layer during burning. The total heat evolved is reduced by 23–28% for using 5–15 wt.% glass and the maximum HRR even by 58–48%. The latter effect decreases with increasing glass amount due to an adulterate residue deformation. The combination of glass and clay is proposed as a possible route to enhance flame retardancy.

Development of polyureas with improved fire resistance

“…By substituting the flammable carbon with silicone, it is believed that the onset decomposition temperature may be increased. 25,26 Another strategy is to synthesize a polymer that is more thermally stable by strengthening the main chain bonds. This can be achieved using the resonance stabilization in aromatic structures.…”

Phosphorus and Silicon Containing Inorganic Polymer Poly(dimethylsilane H‐phosphonate): Synthesis and NMR Spectroscopic Characterization

“…An epoxy hybrid with in situ developed a three‐dimensional inorganic network structure by sol‐gel method displayed higher values of the thermal degradation activation energy than the epoxy resin , . Low melting glasses with O‐P‐O‐Si chain building segments were prepared from orthophosphoric or phenylphosphonic acid with chlorotrimethylsilane (CTMS) or methyltrichlorosilane, respectively, at elevated temperatures up to 200 °C , …”

Flame-Retardant Unsaturated Polyester Resins: An Overview of Past and Recent Developments

“…Layered silicates dispersed in a polymer matrix are the most popular form of hybrid nanocomposites [16,17]. Commonly used MMT-modifying ammonium salts, which contain long alkyl carbon chains in their structure, make aluminum silicates acquire organophilic properties, improve their affinity to a polymer matrix and thus reinforce composites' thermal stability which is determined by the length, number and saturation degree of alkyl chains.…”