The Relationships Between Rheological Characterization And Mechanical Properties Of Nylon1212/POE/POE-g-MAH Reactive Blends

Nylon has many excellent properties,such as low dielectric constant,great dimensional stability,good resistance to strong acid and alkali.However,its toughness is poor at low temperature and dry condition,which has limited it using in the automotive sleeve bearings,electronic appliances,automotive hoses and other industries.Therefore,studies on super-toughness nylon have very important theoretical significance and application prospect.Elastomer,organic rigid particles and inorganic particles can improve the toughness of pure nylon,blending with elastomer is an effective way.The optimal compositions of super-toughness nylon are often acquired based on orthogonal design method,considering various factors and making a lot of orthogonal experiment.How to use a simple experimental method and determine effectively the optimal compositions of super-toughness nylon is an important problem.This study tried to establish the corresponding relationship between the key mechanical parameters and characteristic rheological parameters through investigating the concentration of POE-g-MAH on dynamic rheological behavior and mechanical properties of nylon1212/POE/POE-g-MAH reactive blends.We have prepared nylon1212/POE/POE-g-MAH blends and investigated their mechanical properties,rheological behaviors and morphologies.The results can be summarized as follows:(1)With the concentration of POE increasing,the tensile and flexural strength of nylon1212/POE blends decrease,while the impact strength improve.When the concentration of POE is 20%,the impact strength is 2 times as high as that of pure nylon.(2)For 80/20 nylon1212/(POE/POE-g-MAH)reactive blends,the highest impacting strength is 77.25 kJ/m~2,which is about 4.7 times as high as that of pure nylon1212;For 50/50 blends,the highest impact strength is 67.97 kJ/m~2,which is about 3.8 times as high as that of pure nylon1212.(3)With increasing of POE-g-MAH,the rheological behaviors of nylon1212/POE/ POE-g-MAH reactive blends exhibit "liquid-solid" transition,and the storage modulus curves of the blends show obvious “the second plateau” in the low frequency regions.(4)Both 80/20 and 50/50 nylon1212/POE/POE-g-MAH reactive blends show a gel point in the test regions,are 35% and 10.45%,respectively.The impact strength of two kinds of blends at the gel point show the maximum,which are 84.79 kJ/m~2 and 65.54 kJ/m~2,respectively,indicating that the rheological properties of the blends are related to their mechanical properties.(5)When the blends at the gel point have been impacted,the graft copolymer between nylon1212 and POE-g-MAH can be pulled out from the matrix.The fracture surface of 80/20 blend at gel point exhibited a lot of “rod-like” structure,while 50/50 blend at gel point showed a large amount of “filament-like” structure.