The Study Of The Preparation Of PP/PS Blends By Force Chemical Reactor And Its Computer Molecular Simulation

In the period of today's rapid development of science and technology,the performance of single materials and the use of conditions have been unable to meet the production and living needs.Polymer blends are preferred to be used to complement each other,which makes the overall performance of blends better than the original single material to meet a variety of different needs,therefore,polymer blends are increasingly concerned by researchers.Polypropylene(PP)and polystyrene(PS),the more widely used ones in the five general plastics,due to the limitations of the nature of each of which,need to be blended to achieve desired property.The content of this article includes two aspects of the experiments and simulations of PP/PS binary blending and PP/PS/PP-g-MAH ternary blending.On the one hand,the author studied the PP/PS binary blending and PP/PS/PP-g-MAH ternary blending by the computer simulation software.The first step is using molecular dynamics modules of Materials Studio software,establishing molecular chain,geometry optimization,annealing,dynamics calculation and mechanical property simulation.Then,according to the stiffness matrix and flexibility matrix,the PP and PS mechanical property of young's modulus,shear modulus,bulk modulus and poisson ratio are calculated.In the using of DPD module for PP/PS binary blend system,the author analyzes the phase diagram and the density diagram.Similarly,the DPD module is used to simulate the PP/PS/PP-g-MAH ternary blending system.When the time step is 200000 steps and PP/PS/PP-g-MAH ratio is 90/10/3,the effect of system compatibility is the best,which are also same with experimental results.In order to study the effect of time step to the blending system,a set system of 400000 steps is simulated.On the other hand,in the experiment section,we use laboratory independent research and development of single screw strong shear force chemical reactor for the binary blending of PP/PS,the preparation of PP-g-MAH and the ternary blending of PP/PS/PP-g-MAH.When the screw rotation speed is 50r/min and the ratio of PP/PS is 90/10,the blending materials comprehensive mechanical property is the best.In the condition of different rotation speed and ratio to prepare the compatilizer of PPg-MAH,it is concluded that when the screw rotation speed is 80r/min and PP/MAH/DCP content is 100/3/0.3,the compatilizer of PP-g-MAH grafted rate is highest.Through mechanical property test,when the PP/PS/PP-g-MAH proportion is set to 90/10/3,it is concluded that the comprehensive mechanical property of PP/PS/PP-g-MAH ternary blending material is the best in the screw rotation speed of 50r/min.Considered to increase the shear effect of the screw,the screw structure is optimized designed.By the premeditation of four parameters of max shear rate,max shear stress,max mixing index and cumulative time,the best combination scheme is the angle 60 o of the trapezoidal bottom angle of the spiral cross section and the 1.5mm of top groove of screw arris.