Synthesis Of Graphene Oxide F Unctionalized With P,Si-contained Organic-inorganic Polymer Flame Retardant And Its Application In Epoxy Resin

Epoxy resin is a very important thermosetting resin,which belongs to a kind of organic polymer material.It has many excellent properties,such as strong adhesion and corrosion resistance,which is one of the most common and widely useful resin matrixs.With the development of various fields,the application environment of epoxy resin has become more and more demanding,and its intrinsic performance has been unable to meet the application requirements.Researchers in many countries are working hard to improve various properties of epoxy resin,such as weather resistance,mechanical strength and flame retardancy,etc.Many studies showed that P,N and Si are flame retardant elements.In this paper,MAdiDOPO is used as P-and N-containing molecule,and MAPOSS is used as Si-containing molecule.Two novel DOPO-and POSS-based copolymer modified graphene oxide flame retardants named GO-MD-MP or GO-D-P are designed and prepared,which effectively solve the problems of high flame retardancy and high contain of traditional P,N and Si flame retardants.The research works are as follows:1.The graphene oxide GO was synthesized by the modified Hummers method,and its structure and morphology were characterized by FT-IR,XPS,XRD,Raman spectroscopy,TEM and AFM.In the previous work of our research group,DODO,POSS-based random copolymer P(GMA-co-APOS S-co-MAdiDOPO)was synthesized using MAdiDOPO,MAPOSS and GMA as monomers,and it was connected with GO by the "graft to" method.The GO-MD-MP with DOPO and POSS-based copolymer modified graphene oxide was grafted to the GO successfully.The polymer was successfully grafted to graphene oxide by FT-IR,XPS,XRD and Raman spectroscopy.The thermal stability was analyzed by thermogravimetric test(TGA),and its morphology was analyzed by atomic force microscopy(AFM)and transmission electron microscopy(TEM).2.The graphene oxide was modified with 2-bromoisobutyryl bromide to prepare a graphene initiator GO-Br,followed by in-situ polymerization of MAdiDOPO and MAPOSS by the "graft from" method(ATRP method)to obtain a polymer brush-type functionalized graphene flame retardant GO-D-P.The structure was analyzed by FT-iR,XPS,XRD and Raman spectroscopy.The polymer was decomposed from graphene,its molecular weight was measured by GPC.The thermal stability of GO-D-P was measured by thermogravimetric test(TGA).Its morphology was analyzed by transmission electron microscopy(TEM).3.Two kinds of flame retardant epoxy resin composites GO-MD-MP/EP and GO-DP/EP were prepared.The SEM characterization showed that the flame retardant can be uniformly dispersed inside the matrix,because DOPO and epoxy resin have good compatibility that makes the GO-MD-MP and GO-D-P have strong interfacial bonding ability with the matrix,and no obvious phase separation phenomenon is found.Both flame retardants can improve the amount of carbon residue after burning epoxy resin,and form dense outer carbon residue and bubble-like inner carbon residue.It has excellent flame retardant properties and can pass V-0 grade in the UL-94 test.Because of the good dispersibility of GO-MD-MP and GO-D-P and strong interfacial bonding ability,the mechanical properties of the matrix are enhanced,implying the synergistic flame retardancy and mechanical properties of graphene functionalized organic flame retardant molecules are fully exerted.