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

• Published in: Polymers Vol. 14; no. 9; p. 1708
• Main Authors: Zhou, Ruirui, Lin, Lijie, Zeng, Birong, Yi, Xindan, Huang, Chenyu, Du, Kunpeng, Liu, Xiaohui, Xu, Yiting, Yuan, Conghui, Dai, Lizong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 22.04.2022; MDPI
• Subjects: Addition polymerization; Block copolymers; Chain transfer; Composite materials; Copolymers; Curing; Environmental protection; epoxy resin; Epoxy resins; Ethanol; Fire resistance; Flame retardants; Glass transition temperature; Graft copolymers; Graphitization; Hydroxybenzaldehydes; Imines; macromolecular flame retardant; Mechanical properties; Metal oxides; migration; Nitrogen; Phosphorus; Polyhedral oligomeric silsesquioxane; Polymerization; Polymers; Spectrum analysis; Thermal stability; Ti-POSS; Titanium; United States > US; China; Ti-POSS; migration; macromolecular flame retardant; epoxy resin; phosphorus
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym14091708

In this paper, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing diblock copolymer poly[(p-hydroxybenzaldehyde methacrylate) -b-(2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)oxy)ethyl methacrylate) ] (abbrev. poly(HAMA -b-HEPOMA )) 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) -b-HEPOMA ] (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/H O 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.