Preparation Of Methoxy Polyethylene Glycols Loaded With Alkylaminated Graphene Oxide/Polypropylene Phase Change Fiber

Phase change fiber is a kind of intelligent material which uses the tiny temperature change of matter to store considerable heat energy and has the ability of taking the initiative to adjust the temperature.Porous carrier-based form-stable phase change materials make use of the rich and adjustable surface of the carrier,which has considerable energy storage density,anti-leakage ability and excellent thermal conductivity,so it is an ideal raw material for the preparation of phase change fibers by melt spinning.However,due to the strong internal adsorption and the polarity difference between the form-stable phase change materials and the spinning matrix,this kind of form-stable phase change materials reunite seriously during processing,resulting in unstable flow and spinning discontinuity.At the same time,the activity ability of phase change molecules is weak and the crystallization behavior is difficult,which leads to the decrease of enthalpy and crystallization undercooling.The performance improvement and application range of phase change fibers are seriously limited.In this paper,graphene oxide(GO)with rich surface groups and strong adsorption capacity was selected as carrier material.Through partial alkylamination of oxygen-containing functional groups on the surface of GO,the strong hydrogen bond of"O--H"was replaced by"N--H"weak hydrogen bond to adjust the adsorption strength of phase change material polyethylene glycol monomethyl ether(MPEG).At the same time,nucleating agent microcrystalline cellulose(MCC)was added to promote the crystallization behavior of MPEG.Finally,the compatibilizer polypropylene grafted maleic anhydride(PP-g-MAH)was added into the blend system to further adjust the polarity difference between the fixed phase change material and the spinning matrix,improve the dispersion of the form-stable phase change material in the melt during processing and release the enthalpy of the phase change fiber.Finally,alkylaminated graphene oxide supported methoxy polyethylene glycol/polypropylene phase change fiber was prepared,and the structure and properties of the fiber were explored.The main contents of this paper are as follows:(1)Preparation and study of alkylaminated graphene oxide supported methoxy polyethylene glycol form-stable phase change materials.The carboxyl of GO was alkylated with octadecylamine(ODA)to prepare alkylaminated graphene oxide(GO-ODA),and MCC was added to prepare alkylaminated graphene oxide supported methoxy polyethylene glycol form-stable phase change materials.The structure of GO-ODA was characterized by FTIR,XRD and Raman,and the thermal properties of form-stable phase change materials were characterized by TG and DSC.The results show that the grafting effect is the best when the reflux temperature is 60°C and the reflux time is 12 h;the grafting modification enlarges the lamellar spacing on the basis of retaining the carbon skeleton,increases the disorder,and can meet the melt spinning requirements;under the synergistic action of MCC and GO-ODA,the undercooling of GO-ODA1MCC/MPEG with 1%MCC is 17.6?higher than that of GO-ODA/MPEG,and the enthalpy efficiency is 108%.(2)Preparation and study of methoxy polyethylene glycol/polypropylene composites supported by alkylaminated graphene oxide.Compatibilizer polypropylene grafted with maleic anhydride(PP-g-MAH)and self-made compatibilizer hydroxyl functionalized polypropylene(PPOH)were introduced into SG/MPEG/PP blends with different polarity.The dispersion of the composites was studied by slice observation,SEM and rheological tests.The results showed that PP-g-MAH blends with 5%content had the best dispersion properties,the average diameter of the cross section is less than 2.30?m,and the melt behaves as Newtonian fluid in dynamic frequency scanning mode.Then 5%PP-g-MAH was added into GO-ODA1MCC/MPEG to prepare the composites with a miniature twin-screw blender.The thermal properties of the composites were studied by DSC test and thermal conductivity test.The results show that due to the further weakening of the difference of interfacial polarity,the undercooling of GO-ODA1MCC/MPEG/PP is 5.37?higher than that of GO-ODA/MPEG/PP,and the enthalpy of phase transition is 11.4 J·g^-1.(3)Preparation and study of methoxy polyethylene glycol/polypropylene phase change fiber supported by alkylaminated graphene oxide.Adjust the addition amount of each component in alkylaminated graphene oxide supported polyethylene glycol monomethyl ether/nucleating agent/compatibilizer/polypropylene spinning formula,a series of phase change fibers were prepared by using micro twin screw blender and micro winding machine.The internal structure and phase transition properties of the fiber were studied by slice observation,DSC and cyclic DSC test,heat storage/exothermic test and thermal conductivity test.The results show that when 1%MCC is added to methoxy polyethylene glycol supported by alkylaminated graphene oxide and 5%PP-g-MAH is added to the phase change fiber,the internal FSPCM distribution is uniform.Compared with the pre-spinning chip,the undercooling is further increased by 2.06?,and the enthalpy efficiency is up to 95.3%.The temperature lag of the fiber is68 s in the heating process and 61 s in the cooling process,and the maximum hysteresis temperature difference is 5.50?.The fiber has excellent active temperature regulation and thermal energy storage capacity.