Research On Acrylonitrile Copolymer Backbone Grafted Side Chains Solid-solid Phase Change Materials

To expore the green and non-polluting new energy,save energy and increase energy efficiency have become the most pressing topic because of the energy crisis,the high cost of fossil fuels and the environmental impacts.Phase change storage technology is the effective mean to improve energy use efficiency and protect the environment,so the study of phase change materials has been one of the central issue in the energy storage field of materials.In this paper,the object of research is based on molecular design,constructing the"active"skeleton of acrylonitrile copolymer.Than,the acrylonitrile graft copolymers were synthesized successfully as new solid-solid phase change materials,by grafting or crosslinking the phase change unit to the"active"skeleton.The phase change units such as fatty acid,polyethylene glycol or derivatives.And the chemical structure,thermal energy storage properties,microstructure structure and machinability were systematically characterized.The as-synthesized phase change materials owns excellent phase change properties,suitable phase change temperature,and good thermal stability.Therefore,the as-synthesized phase change materials were promising material with great potentials in various applications.The specific research contents of this subject include the following aspects:1.We select Palm acid(PA)as phase change unit and Poly(styrene-co-acrylonitrile)(SAN)as main chain skeleton,successfully synthesize a series of novel solid-solid phase change materials.The results show that the phase transition temperature of the phase change material within the range of 23.9~48.1?,and the enthalpy was around 24.4 J/g.On this basis,we choose SAN-g-PA as a compatibilizer,successfully prepared the SAN/SAN-g-PA/Lauric acid(LA)composite fiber materials and nanofibers by blending method.2.Poly(styrene-co-acrylonitrile)-g-polyethylene glycol(SAN-g-PEG)solid-solid phase change materials was prepared successfully with PEG as phase change unit and chloride as"bridge group".The results show that the phase change materials have suitable phase change temperature,and the enthalpy was around 124.6 J/g.Moreover,it proves that phase change materials appeared good thermal stability,heat storage durability with a T_d of 344?.And it was observed that the PEG and SAN had a excellent compatibility by investigation of the structure of the SAN-g-PEG using a SEM,the overall form of a continuous phase,no"island"structure.3.We select hydroxyethyl methacrylate(HEMA)as the monomer and MPEG(PEG)as phase change unit.Than the P(AN-co-HEMA)-g-MPEG was synthesized as new solid-solid phase change materials(AHPCMs).To investigate the extent of MDI and MPEG reaction by using a IR,and determine the structure of AHPCMs.It was found that AHPCMs solid-solid phase change materials has good phase change energy storage properties.When the MPEG4000 is selected as the phase change unit,the enthalpy values up to 115.1 J/g.4.We further to prepared a new phase change macromonomer MAMPEG1000,namely,P(AN-co-MAMPEG)with a controlled molecular weight and molecular weight distribution was prepared by atom transfer radical polymerization(ATRP).The results showed that the synthesized P(AN-co-MAMPEG)by ATRP has a better reaction controllab ility,and narrow molecular weight distribution.The content of phase change macromonomer of P(AN-co-MA-MPEG)is 38%.And it has the function of phase change energy storage.The method is further to extended controllable polymerization application in the field of phase change materials.