Study On The Properties And Structures Of Polyethylene Of Raised Temperature Resistance

Polyethylene resin is the most general used thermoplastic resin with the excellentperformance to resist low temperature, and easy to process. The uncrosslinked polyethylenecan be simply recycled and reused by people. As the shortage of oil resources, recycling theuncrosslinked polyethylene is widely accepted by people, the result is protecting theenvironmentandreusingtheresource.But polyethylene is limited to its use, such as the strength of the ordinary polyethylene isnot strong,. In general, its strength is not stronger than the strength of polypropylene. Theproductsofpolyethylenecannotbeusedintheabove50℃environmentforalongtime.For linear polyethylene, the larger the molecular weight, the longer the molecularchain and the slower crystallization rate. The crystallizaiton rate is strongly affected bythe interactions and entanglements between the long chain molecules. The mainresearch contents of this paper are as follows:1.For polyethylene products, the low resistance environmental stress cracking isdue to the portion of the low molecular weight polyethylene as the destruction position.But the larger the molecular weight, the higher the viscosity, it can not be easilydispersed into the high density polyethylene. So the small portion of high molecularweight polyethylene is added into the high density polyethylene system. In my research,three percents and five percents of two kinds of high molecular weight polyethylene isadded into the high density polyethylene to improved the properties of high densitypolyethylene under unaxial tension, the viscosity average molecular weight is respective900thousands and2.5millions. The study found that five percents of high molecularweight polyethylene of900thousands and three percents of high molecular weightpolyethylene of2.5millions in the blend system under unaxial tension. The crystallinityincreased by7.84%and10.13%, the tensile yield strength increased by18.5%and21.2%, and vicatsoftening temperature and storage modulus were increased,respectively. The melt index test, torque rheometer plasticizing behavior analysis, anddynamic rheological behavior of the blends, those show the blends can be processed.2.Preparing one kind of high molecular weight and long branched polyolefinmasterbatch as the modifier of high density polyethylene. The study found that10percents of masterbatch and0.1percent of nucleating agent into the high densitypolyethylene. The crystallinity increased by4.14%, the tensile yield strength increasedby16.5%, and vicatsoftening temperature and storage modulus were increased,respectively. The melt index test, torque rheometer plasticizing behavior analysis, anddynamic rheological behavior of the blends, those show the blends can be processed.