Thermoplastic Polyolefin And Nylon: Reinforcing, Toughing And Their Strueture- Propertiy Relations

Pyroplasticity Polyolefin and nylon are notch-sensitive polymer. It is generally known that polyethylene and polypropylene are widely used due to their good processing properties and relatively low cost. However, low toughness and rigidity limits their further application in engineering field. Nylon is widely used in engineering applications. But its further application is limited by the notch sensitivity, the lack of stability of dimension and higher absorption of moisture. Thus, improving the toughness and rigidity of polyethylene, polypropylene, and Nylon becomes an important research topic in both polymer science and engineering. In this study, the degraded polypropylene by DCP was toughened by EPDM, polyethylene was toughened by rigid particles glass bead and nano-SiO2, nylon 6 was toughened by ABS, nylon 66 was toughened by POE-g-GMA, and the structure and property of the resulting materials was systemically studied. The following results were obtained.1. When PP was degraded by DCP and degraded PP/EPDM blends was prepared. The toughening change rule of degradation PP/EPDM blends with test impact strength of blends at different temperature. We have got the relation of the brittle-ductile transition temperature and the EPDM content in degraded PP/EPDM blends at brittle-ductile transition spot. The influences on brittle-ductile transition of the degraded PP/EPDM blends by the temperature and the EPDM content are equivalent, and the degraded PP/EPDM blends will be brittle-ductile by increasing temperature or increasing EPDM content, thus, the brittle-ductile transition temperature can be reduced when increasing EPDM content. The correlation between the critical interparticle distance (IDc) and temperature was successfully obtained, in degraded PP/EPDM blends at brittle-ductile transition spot. Similar to the results of thermoplastic/elastomer blends, it was found that the EPDM can be well-dispersed in matrix. At normal temperature the tensile strength of degraded PP/EPDM blends decreases with the increase of EPDM content, The elongation at break decreases with the increase of EPDM content, and it is down to minimum when the EPDM content is 12%, then the elongation at break increases with the increase of EPDM content. DSC and XRD result shows that Degraded PP spherulite growth of three-dimensional way. EPDM has impact on the crystal morphology, grain size distribution of degraded PP.2. Polyethylene was toughened by rigid particles glass bead and nano-SiO2. The affecting factors of PE with rigid particles, such as treatment of coupling agent, matrix toughness, and its content were studied. Its structure and properties were studied by mechanical property testing and electron microscopescanning. It is obvious that the silane coupling agent is beneficial to the GB and nano-SiO2 dispersion in matrix, Rigid particles dosage has a critical point-it is 25 percent to PE/GB blends and 3 percent to PE/nano-SiO2 blends. The critical point of nano-SiO2 blends is smaller than PE/GB blends. From the blends impact cross-section micromor-phologies, we can see blends impact present ductile fracture and apparent plastic deformation.3. Nylon 6/poly(acrylonitrile-butadiene-styrene)(ABS) blends were prepared by a twin-screw extruding machine. Maleic anhydride copolymer and solid epoxy resin were used as compatibilizers for these blends. The effects of compatibilizers were studied by torque test, mechanical property test, morphology testes and DSC analysis. The results show that the additions of epoxy and MA copolymer into nylon 6/ABS blends appeared to enhance the compatibility between nylon 6 and ABS, enhanced the toughness of blends greatly. The tensile strength and notched impact strength of nylon 6/ABS blends are both improved, while the thermostability is not changed. Therefore, the purpose of toughening and reinforcing was reached.4. In DCP initiator, the GMA for active monomers preparated POE-g-GMA, by melt blending process. study on effect factor of POE-g-GMA. In the best technical conditions for:DCP content take 0.5%, GMA content in 6%, reaction temperature 170℃, reaction time took 6-10min, POE-g-GMA can effectively toughening PA66. While POE-g-GMA content is up to 30%, blends notched impact strength increased to 4 times that of matrix PA66.