Preparation And Performance Research Of Polyurethane/Microcapsules Foam Composites

Polyurethane foam is a kind of easy- forming polymer material with porosity, low density, ageing resistance and resistance to organic solvent,which has been widely used in construction, packaging and other fields.But the pure polyurethane foam has poor heat storage and temperature adjustment function, and it has poor flame retardancy. It limits its application in some special fields. Polyurethane foam modification methods include filling modification, morphology and structure modification(copolymerization,crosslinking, grafting modification), compound modification, surface modification and so on. In this paper, using filling modification, the phase change material microcapsule and expandable graphite microcapsule with core-shell structure are added to the polyurethane matrix. The introduction of microcapsule’s shell material effectively improves compatibility between polyurethane matrix and microcapsules.So thermal storage property,flame retardant property and mechanical property of polyurethane foam composite are improved. The main content of this paper are as follows:1.Using in-situ polymerization, octadecane as core material and polymethyl methacrylate as wall material, the phase change material microcapsules Micro PCM are prepared.Three kinds of emulsifiers, alkylphenol ethoxylates(OP – 10), sodium dodecylbenzene sulfonate(SDBS) and styrene and maleic anhydride copolymers(SMA) are used. The core material encapsulation efficiency of Micro PCM with SMA as emulsifier is 48.92%,and ?Hm and?Hc of Micro PCM with SMA as emulsifier are 106.25 J/g and 104.1 J/g, respectively. Also it has the best dimensional homogeneity, so emulsifying effect of SMA is the best.2.Adding Micro PCM with SMA as emulsifier into the polyurethane matrix,Micro PCM/PU composite foam material is prepared. DSC test shows that Micro PCM/PU composite foam is possessed of endothermic and exothermic peaks, and ?Hm and ?Hc of Micro PCM/PU composite foam containing 12 wt % Micro PCM are 8.031 J/g and 8.887J/g. Pure polyurethane foam does not have any exothermic peak or endothermic peak,indicating that polyurethane foam containing Micro PCM has the certain functions such as thermal storage, insulation and regulating temperature.TGA test shows that Micro PCM doesn’t change the thermal decomposition mechanism of polyurethane.3.Using in-situ polymerization, expandable graphite as core material and polymethyl methacrylate as wall material, the expandable graphite microcapsule PMMA-EG are prepared. Then the interfacial compatibility is improved by the microcapsule’s shell material,and mechanical property of EG/PU foam composite are improved. When the content of PMMA-EG is 10 wt%,PMMA-EG/PU composite foam’s compression strength increases to 0.146 MPa, compression modulus increases to 67.984 MPa.4.Horizontal burning rate of EG/PU composite foam is 0.62×10-3m/s,and its LOI value is 22.5%.After the introduction of microcapsule’s shell material PMMA, horizontal burning rate of PMMA- EG/PU composite foam decreases to 0.59×10-3m/s,and its LOI value increases to 24%.