Preparation And Application Of Phase Change Materials Shape-stabilized By Interpenetrating Networks

In this study, phase change materials Shape-stabilized by InterpenetratingNetworks(FSPCM) were prepared,which could be used in a high temperature environment.And blended it with polypropylene(PP) to produce phase transited fiber by melt spinningpreparation.In this study, orthogonal test method was used. FSPCM with three-dimensional networkstructure was prepared by free radical polymerization,using N-hydroxymethylacrylamide(NHMPA) as monomer, N, N-methylene bisacrylamide(BIS) as the crosslinkingagent, and ammonium persulfate(APS) as initiator, in water solvent system. The heat storagedcapacity of the FSPCM was sutdied. The impacts of various experimental factors to the heatstorage capacity were discussed, and the best process was determined. Results show that, thebest process is PEG mass fraction is70%, molar ratio of crosslinking to monomer is1:8,ratio of monomer to water is1:6，reaction time is3h,initiator concentration of total monomeris2.5%. Structure and properties of FSPCM were synthesized by scanning electronicmicroscope(SEM), differential scanning calorimeter(DSC) and thermogravimetricAnalysis(TGA). DSC test showed that the PSPCM had good heat storage capacity, SEM testshowed that there was three-dimensional network structure in the vector. TGA test showedthat the vector weight loss began from300℃which could meet the requirements ofpost-spinning.Blended the FSPCM with PP to produce phase transited fiber by melt spinningpreparation. Structures and properties of blend and fiber were studied by capillary rheometer,torque Rheometer, polarization microscope(POM), dynamic mechanics analyzer(DMA),SEM,DSC, monofilament strength tester. The rheology test showed that the blend waspseudoplastic fluid, its viscosity decreased with the increasing of temperature, shear rate andthe mass fraction of FSPCM. POM test showed that FSPCM could play the role ofheterogeneous nucleation in the PP matrix, ppherulite number of blend increase. DMA testshowed that wtih FSPCM added to the polypropylene matrix, the storage modulus and loss modulus had been improved, with the amount increasing, both also increased, the lossfactor tanδ lower than pure PP. SEM observation showed that the FSPCM in the spinningfibroin within distributed more evenly, and because of FSPCM existence, the fiber surfacesmoothness slightly lower. DSC results indicated that the enthalpy increased gradually withthe FSPCM increasing content in the phase transited fiber, when the phase change materialcontent was20%, the enthalpy up to30.08J/g. The tensile test results showed that when theFSPCM content was5%, tensile strength increased slightly, as4.78cN/dtex, after the contentcontinued to increase, the fiber fracture strength of the overall showed a downward trend, thelargest decline in the proportion was26.74%when the phase change material content was20%, but breaking strength is still more than3.48cN/dtex. Wtih FSPCM added to thepolypropylene matrix, the moisture absorption of the blend fiber increased, the maximummoisture regain up to0.68%.In summary,with the content of FSPCM of20%, while maintaining a relatively stable ofthe spinnability, blend fiber has good overall performance. Enthalpy was30.08J/g, breakingstrength of fiber was3.48cN/dtex, and s have a0.68%moisture regain.