Biobased polyelectrolyte multilayer-coated hollow mesoporous silica as a green flame retardant for epoxy resin

• Published in: Journal of hazardous materials Vol. 342; pp. 689 - 697
• Main Authors: Jiang, Shu-Dong, Tang, Gang, Chen, Junmin, Huang, Zheng-Qi, Hu, Yuan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.01.2018
• Subjects: carbon; cellulose; chitosan; coatings; combustion; electrolytes; electrostatic interactions; epoxides; Epoxy resin; fire safety; flame retardants; Green flame retardant; heat; Hollow mesoporous silica; Polyelectrolyte multilayer; polymers; porous media; silica; silicon; Sustainable recycling; thermal properties; value added; Epoxy resin; Green flame retardant; Hollow mesoporous silica; Polyelectrolyte multilayer; Sustainable recycling
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2017.09.001

•A green flame retardant (HM–SiO2@CS@PCL) was successfully synthesized through layer-by-layer assembly.•The integrated effect of HM–SiO2@CS@PCL endows epoxy resin with excellent flame retardancy.•The incorporation of HM–SiO2@CS@PCL can recycle epoxy resin into high value-added hollow carbon spheres. Here, we describe a multifunctional biobased polyelectrolyte multilayer-coated hollow mesoporous silica (HM-SiO2@CS@PCL) as a green flame retardant through layer-by-layer assembly using hollow mesoporous silica (HM-SiO2), chitosan (CS) and phosphorylated cellulose (PCL). The electrostatic interactions deposited the CS/PCL coating on the surface of HM-SiO2. Subsequently, this multifunctional flame retardant was used to enhance thermal properties and flame retardancy of epoxy resin. The addition of HM-SiO2@CS@PCL to the epoxy resin thermally destabilized the epoxy resin composite, but generated a higher char yield. Furthermore, HM-SiO2 played a critical role and generated synergies with CS and PCL to improve fire safety of the epoxy resin due to the multiple flame retardancy elements (P, N and Si). This multi-element, synergistic, flame-retardant system resulted in a remarkable reduction (51%) of peak heat release rate and a considerable removal of flammable decomposed products. Additionally, the incorporation of HM-SiO2@CS@PCL can sustainably recycle the epoxy resin into high value-added hollow carbon spheres during combustion. Therefore, the HM-SiO2@CS@PCL system provides a practical possibility for preparing recyclable polymer materials with multi-functions and high performances.