Study On Relaxation Mechanism And Model Of Polystyrene In High Elastic State

With the rapid development of today's society,polymer materials have become a material with a high frequency of use and a wide range of applications.During the actual processing of the polymer,the changes in its relaxation behavior affect the curing time of the processed product and the internal residual stress after curing.At the same time,for amorphous polymers,they have undergone glass transition and visco-fluid transition in the actual processing process.And there is no set of a more accurate and authoritative theoretical system to intuitively in the current research.Therefore,the purpose of this paper is to study the relaxation mechanism and model of amorphous polymers under high elasticity and the conditions of practical application,which has important theoretical guiding significance for solving the above problems.As one of the"five general-purpose plastics",polystyrene has relatively high precision requirements for processed products.Therefore,this article selected polystyrene as the research object,based on the conclusions of the experimental findings,deeply analyzed the molecular chain movement mechanism,and the relaxation time physical model of polystyrene under high elasticity was bulid.And mathematical prediction model of relaxation time of polystyrene under high elasticity was constructed by analyzing the influence of the microstructure parameters of polymer materials on their relaxation behavior,and combining the changes in external conditions.In this paper,Fourier Infrared Spectroscopy(FT-IR)and Gel Chromatography(GPC)are used to test the structure and performance of different polystyrene materials,the test results are compared and analyzed.According to the analysis results,a representative grade of polystyrene was choosed.Meanwhile,Differential scanning calorimetry(DSC)was used to determine the glass transition interval of different grades of materials,the value of the estimated viscosity fluidization temperature T_fwas analyzed,and the difference between the high elastic temperature and the high and low deformation properties was used to select the appropriate experimental temperature range.Based on the conclusions of the above tests,a representative sample of polystyrene was selected for repeated relaxation time determination tests,and the effect of relaxation time with changes in external conditions was found.Based on the conclusions of the experimental findings,the theoretical model study was started in this paper.Firstly,based on the related theoretical knowledge,in-depth analysis was carried out to obtain the movement mechanism of polystyrene molecular chain with the change of external conditions,and the relaxation time physical model of polystyrene under high elasticity was established.After analysis,as the external conditions(temperature T,speed N)change,the relaxation time(?_E,?_V,?_?)affected by various microscopic factors in the physical model would change.Then,based on the effects of micro parameters of polymer materials and external conditions on the relaxation time of polystyrene under high elasticity,temperature T,rotation speed N,weight average molecular weight M_w,and molecular weight distribution parameter D were the main parameters to construct polystyrene mathematical prediction model of relaxation time of polystyrene.For other brands of polystyrene samples,the relaxation time was measured according to the determined experimental conditions.Through analysis of the experimental and model fitting results,it was found that the change trends of the two were consistent,and the experimental data was relatively consistent as a whole after removing the influence of error factors such as the feeding speed and the external force during pressing.Under the mutual coupling of molecular weight distribution index D and molecular weight,the variation amplitude of different samples has certain differences.The results of this study can accurately control the curing time of polymer processed products and the residual stress inside the cured product on the accuracy of polystyrene processed products through the selection of material structure parameters and external condition parameters.At the same time,for high-precision parts and equipment related to polystyrene materials,it has a certain role to promote its occupation of domestic and foreign markets.In addition,the results of this study can be extended to other polymer materials,which is of great significance to the development of the polymer field.