Study On Synthesis Of Hyperbranched Polyester And Modified Polypropylene Fiber

Dentritic polymers which contain Dendrimer and Hyperbranched polymer are a brandnewseries of polymers and have widespread application prospect. Among them,Hyperbranchedpolymer is more popular for its simple method of synthesis.Hyperbranched polymers show some special properties such as low viscosity,highsolubility,etc,for their three-dimension and ellipsoid-like molecule architectur,a multitude ofinner holes,modified end groups and no inter chain entangling. So then can be applied aspolymer blending modifier to improve process and capability of polymer.Polypropylene is one of the most applied resins for its execellent performance. However,the molecule structure of polypropylene is very tight without groups to link the dye moleculeinto the main chine,so dye molecule can not infiltrate in and consolidte into the fibers. Thisdifficulty has been the focus for people. A great quantity of nner holes in hyperbranchedpolymer can load small molecule, such characteristic can assist dye molecule infiltrate andconsolidate in the fiber, so the staining property may be improved.A brandnew kind of hyperbranched polyester was synthesized in this study. Its averagemolecular weight range is from1629.835315.77,and the kinetics was studied.Hyperbranched polyester was applied as modifier to blend with Polypropylene. The blendratio was1%8%. Mechanical property,rheological property and staining property of blendswere studied here.The results revealed that the reaction system was a constant temperture and constant pressone, and a first order reaction whose rate constant was1.589×10-2mol^-1·dm3·min^-1. Theblending system was all non-Newtonian shear-thinning fluid. And its apparent viscositydecended with increasing the shear rate,process temperature and the content of hyperbranchedpolyester. The non-Newtonian index dropped with the increasing content of hyperbranchedpolyester. All these could prove that the rheological property was improved. The viscous flowactivity energy ascended to45.34kJ·mol^-1,and the temperature dependence of viscosityincreased with increasing hyperbranched polyester content. The staining property ofpolypropylene fiber was improved with hyperbranched polyester,the dye-uptake of dispersing dye ascended to61%when the hyperbranched polyester content was6%.The mechanicalproperty of polypropylene fiber was improved when the hyperbranched polyester content waslittle,got maximum when the hyperbranched polyester content was5%.