Polyolefin Reaction Out Of The Graft And High Toughness Of Polyamide Engineering Plastics

In this paper, the reactive mechanism, processing conditions, optimized recipe, grafting rules, application of grafting product and so on are analyzed by studying grafting MA onto polyolefin backbone in a specific designed extruder. Ultra toughness PA66 alloy is prepared by blending grafted polyolefin with PA66, and its mechanics properties and microphase structure are analyzed.The major works of this study are summarized as following:1.In the course of experiment, single-screw reactive extruder (30 type) of our lab was improved including changing-net wares of extruder heading, melt press sensor, and exhaust system etc. in order to improve product quality. At the same time I took part in designing, fabricating, fixing and debugging of industrial reactive extruder (90 type) successfully.2.The mensuration of grafting efficiency is improved greatly.3.In this paper, systematic study has carried out on the reactive mechanism, processing conditions, optimized recipe of powdery/granular high-density polyethylene (HDPE ) grafting MA. The influences of the choice of dispersant, the dosage of MA and DCP, the temperature of reactive zone on grafting efficiency (Gx) and melt index (MI) were studied. The results show that grafting product of powdery HDPE is better than granular HDPE in most aspects.4. This part analyzed the influences of the dosage of DCP and antioxidant 1010, the choice of dispersant and the temperature of extruder heading on Gx and MI of linear low-density polyethylene (LLDPE) grafting products. Simultaneously, the grafting products were used as hot melting adhesive on iron-pipe protection. The effect of grafting degree and different kinds of LLDPE on peeling strength was carried out systematically. The industrialization of products has been completed in Dalian.5.The PP-g-MA product (Gx=8.1mmol/100g) was produced on the optimized recipe and processing conditions based on former experiments. There is very little resident MA monomer in the PP-g-MA product by the chemical and IR analyses, and injection experiments show that it doesn't affect application of the PP-g-MA. Wild angle X-ray diffraction (WAXD) of PP-g-MA and PP were examined and found that their crystalline phases were unchanged, but the diffraction intensities low of PP-g-MA increased compared with that of PP. Synchronously, a^ c axes of lattice parameters were changeless but b axis decreased. Analysis of rheology led to the conclusion that PP-g-MA and PP still were non-Newtonian false plastic liquid.6. Three kinds of alloy(HDPE-g-MA/ PA66, LDPE-g-MA/ PA66> PP-g-MA/ PA66) were prepared by twin-screw extruder. Molau experiment found that grafting polyolefin and PA66 determinately occurred reaction. Mechanic property and microphase structure were studied systematically. The results show that the compatibilization of HDPE-g-MA and LDPE-g-MA is better. The rupture mechanism of alloy may be sheering mechanism, because tensile specimens of HDPE-g-MA/PA66N LDPE-g-MA/PA66 appears necking in the course of tensile experiment, and SEM of breaking surface show that alloy rupture belong to ductile breaking. Comparing three type of alloy, mechanic properties of HDPE-g-MA/PA66 is the best and product has good appearance, higher notched impact strength, lower moisture content when the content of HDPE-g-MA is 20%~30%.