Study On The Preparation And Properties Of CPCM/PA6 Thermo Regulating Fibers

Thermal regulating fiber is a kind of smart fiber which is constituted of phase change materials(PCMs)and matrix polymers,and takes advantage of the latent heat that can be stored or released from the PCMs over a certain temperature range.At present,the single PCM being used for the thermal regulating fibers always have a narrow phase change temperature range and lower latent heat.What’s more,thermal regulating fibers were prepared by wet-spinning,microcapsulary or hollow fibers filling which included some disadvantages such as complex spinning process,high cost and low filling rate of PCMs.In this paper,a novel kind of thermal regulating fiber with composite phase change material(CPCM)and polyamide 6(PA6)as core and sheath,respectively,were prepared via melting composite spinning with a composite spinning pack made by ourselves,it could be use in winter warm coat.In this paper,firstly,three different single PCMs were assembled into two types of CPCMs.Select the target CPCM with appropriate phase change temperature range and higher enthalpy via DSC,then DSC,FTIR,TGA were employed to investigate its structure and properties.Besides,the thermal and chemical stability were tested by thermal circulation experiment.In addition,the isothermal crystallization and the non-isothermal crystallization kinetics of CPCM was studied by DSC using the Avrami equation,Jeziomy method,Ozawa method as well as Mo method.Then prepared the CPCM/PA6 fiber via melting composite spinning and studied on the effect of spinning process such as CPCM content,temperature,widing rate,drawing temperature and drawing ration on the properties of fiber to concern the optimal spinning procedure.Finally,the structure and properties of optimum fiber were tested by DSC,SEM,FTIR,TGA and tensile strength tester.The study on the preparation and properties of CPCM showed that the melting and crystallizing temperature ranges of the 30/70 ester B/alcohol A CPCM were 18.23 ℃-32.23 ℃ and 20.86 ℃～11.74 ℃,respectively,and the melting and crystallizing enthalpies were 206.4 J/g and 195.8 J/g,respectively.The CPCM after the repeating use still maintained a good thermal and chemical stability.As a result,the CPCM could be applied to inner piece of winter warm coat.The study on the crystallization kinetics of CPCM showed that the Avrami equation was successfully used to describe the isothermal crystallization process of CPCM,the values of n was about 3 and the △E was 19.55 KJ/mol;As the temperature increased,t1/2 and tmax.increased while Zt decreased.It was found that the Jeziorny method,Ozawa method and Mo method were successfully used to describe the non-isothermal crystallization process of CPCM.As the cooling rate increased,t1,2 and tmax.decreased while Zc increased.The values of n,m,b were about 2.99～3.300.90～3.98,1.27～1.40,respectively,and the AE was 300.1 KJ/mol in the non-isothermal crystallization process.The effects of fore-spinning process and drawing process of fibers were shown that as the CPCM content increased,the melting and crystallizing temperature range shifted to the higher temperature,and the enthalpies increased markedly;as the temperature increased,the melting and crystallizing temperature ranges had a little change,and the melting and crystallizing enthalpies increased firstly and then decreased;As the winding rate increased,melting and crystallizing temperature ranges had a little change,and the melting enthalpies increased while the crystallizing enthalpies increased firstly and then decreased;As the drawing temperature increased,the tensile strength increased firstly and then decreased while the thermal properties had a smaller change;As the drawing ratio increased,the tensile strength increased significantly while the thermal properties had a smaller change.The best fore-spinging process were as follow:the injection rate of CPCM was 8 ml/h,the spinging temperature was 245 ℃ and the winding rate was 90 m/min.The best drawing process were as follow:the drawing temperature was 80 0C and the drawing ratio was 5.The structure and properties of CPCM/PA6 fiber were demonstrated that the melting and crystallizing temperature ranges of fiber were 18.50 ℃-30.89 ℃ and 18.68 ℃-7.78 ℃,and the melting and crystallizing enthalpies were 66.12 J/g and 64.93 J/g,respectively.The fibers are core-sheath structured and the cross-sections of it are almost round.The thermal regulating fibers consist of CPCM and PA6,and the CPCM content of fibers is about 32.9%.The linear density of the fibers is 15.57 dtex,and the tensile strength and breaking elongation were 2.76 cN/dtex and 16.71%,respectively.