Optimization of PP Shrinkage Reduction Based on the DOE Experimental Design
In this paper,the effects of talcum powder(Talc),ethylene-octene copolymer(POE),linear low density polyethylene(LLDPE)and nucleating agent Di[2,2′-methylene bis(4,6-di-tert-butylphenyl)phosphate]hydroxyl aluminum salt(TMP)with different contents on the polypropylene(PP)shrinkage were analyzed by using the full factor design in the design of experiment(DOE).The interactions among Talc,POE,LLDPE,and TMP were also analyzed.The results show that Talc has a certain interaction with the others,but the effect is very weak.From the point of view of the contribution to the shrinkage,POE>LLDPE>Talc>TMP,the shrinkage could be as low as 0.2%.The shrinkage,bending modulus,and the Izod notched impact strength of the PP/LLDPE/POE terpolymer system with a total number of 45 parts were analyzed by using the mixture design in DOE.The results show that the optimal ratio is selected as follows:the content of PP is 27.3 parts,the content of LLDPE is 17.7 parts,and the content of POE is 0 part.The shrinkage is 0.58%,the bending modulus is 1 250 MPa,and the notch impact strength is 36 kJ/m2.LLDPE and POE could promote the dispersion of each other in PP,but this enhanced dispersion effect is actually not conducive to reduce the shrinkage.Because the improvement of compatibility among the three components increases the regularity of the material to a certain extent,resulting to a slight increase of crystallinity.This ultimately leads to an increase of the shrinkage.
万方数据
维普
