Diblock Copolymers Containing Titanium-Hybridized Polyhedral Oligomeric Silsesquioxane Used as a Macromolecular Flame Retardant for Epoxy Resin

Ruirui Zhou; Lijie Lin; Birong Zeng; Xindan Yi; Chenyu Huang; Kunpeng Du; Xiaohui Liu; Yiting Xu; Conghui Yuan; Lizong Dai

doi:10.3390/polym14091708

Diblock Copolymers Containing Titanium-Hybridized Polyhedral Oligomeric Silsesquioxane Used as a Macromolecular Flame Retardant for Epoxy Resin

Polymers (Basel). 2022 Apr 22;14(9):1708. doi: 10.3390/polym14091708.

Authors

Ruirui Zhou^{1

2}, Lijie Lin^{1

2}, Birong Zeng^{1

2}, Xindan Yi^{1

2}, Chenyu Huang¹, Kunpeng Du¹, Xiaohui Liu^{1

2}, Yiting Xu^{1

2}, Conghui Yuan^{1

2}, Lizong Dai^{1

2}

Affiliations

¹ Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, China.
² Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen 361005, China.

Abstract

In this paper, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing diblock copolymer poly[(p-hydroxybenzaldehyde methacrylate)_m-b-(2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)oxy)ethyl methacrylate)_n] (abbrev. poly(HAMA_m-b-HEPOMA_n)) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. When it was continued to react with titanium-hybridized aminopropyl-polyhedral oligomeric silsesquioxane (Ti-POSS) through a Schiff-base reaction, new grafted copolymers poly[(Ti-POSS-HAMA)_m-b-HEPOMA_n] (abbrev. PolyTi) were obtained. Then, they were used as macromolecular flame retardant to modify epoxy resin materials. The thermal, flame retardant and mechanical properties of the prepared EP/PolyTi composites were tested by TGA, DSC, LOI, UL-94, SEM, Raman, DMA, etc. The migration of phosphorus moiety from epoxy resin composites was analyzed by immersing the composites into ethanol/H₂O solution and recording the extraction solution by UV-Vis spectroscopy. The results showed that the added PolyTi enhanced the glass transition temperature, the carbon residue, the graphitization of char, LOI, and mechanical properties of the EP/PolyTi composites when compared to pure cured EP. Furthermore, the phosphorus moieties were more likely to migrate from EP/DOPO composites than that from EP/PolyTi composites. Obviously, compared with small molecular flame retardant modified EP, the macromolecular flame retardant modified EP/PolyTi composites exhibited better thermal stability, flame retardancy, and resistance to migration.

Keywords: Ti-POSS; epoxy resin; macromolecular flame retardant; migration; phosphorus.

Abstract

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