The Effects of DOPO-g-ITA Modified Microcrystalline Cellulose on the Properites of Composite Phenolic Foams

In order to improve the comprehensive performance of phenolic foam,9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)was grafted with itaconic acid(ITA)(DOPO-g-ITA)to modify microcrystalline cellulose(MCC).DOPO-g-ITA modified MCC(DIMMCC)was used to prepare composite phenolic foam(DCPF).The structures of DIMMCC were verified by Fourier transform infrared spectroscopy(FT-IR).The microstructure and crystalline property were characterized by scanning electron microscope(SEM)and X-ray diffraction(XRD)respectively.Compared with MCC,the crystallinity of DIMMCC was dramatically decreased,but the diffraction peak positions were unchanged.Thermal stability was decreased,and T_(i)decreased by 45.0°C.The residual carbon(600°C)was increased by 22.34%.With the dosage of DIMMCC/PR increased,compared with PF,the mechanical properties and flame retardancy of DCPF were increased.Especially,the dosage of DIMMCC/PR was 10%,the comprehensive properties of DCPF was better than others.

Synthesis and Characterization of DOPO-g-CNSL and Its Effect on the Properties of Phenolic Foams

In order to improve the mechanical properties without reducing its flame retardancy of phenolic foams(PFs),9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)was introduced in the structure of cashew nut shell liquid(CNSL)to improve its flame retardant,and the product of DOPO grafting CNSL(DOPO-g-CNSL)was obtained to modify phenolic resin,and to prepare DOPO-g-CNSL modified PFs(DCMPFs).The structures of DOPO-g-CNSL were verified by Fourier transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance(1H-NMR).Compared with CNSL,thermal stability of DOPO-g-CNSL was decreased and Ti decreased by 3.53%,but the residual carbon(800°C)was increased by 35.05%.Compared with pure PF,the mechanical properties,toughness and flame retardancy of DCMPFs were increased when the ratio of DOPO-g-CNSL to phenol(DOPO-g-CNSL/P)was no more than 10%.With the dosage of DOPO-g-CNSL/P increased,Ti of DCMPFs was slightly increased,but the carbon residues(800°C)were almost unchanged.And the cell sizes of DCMPFs were basically the same as the pure PF.By comprehensive analysis,the suitable dosage of DOPO-g-CNSL/P was no more than 10%.