Hyperbranched Polyester,Preparation And Application In Plastics Processing

Hyperbranched polymer is a king of high molecular weight polymer,of which is charactered by high degree of branching and the three-dimensional stereo structure of dendritic,and therefore got the name of the dendritic polymer.Hyperbranched polyester is characterized by ester group,many reactive end groups functional groups and cavity volume are contained in outer layer.Hyperbranched polymers have been widely used in many fields due to its low viscosity,high dissolution and the advantages of good film forming.In this research,hyperbranched polyesters were synthesized from 2,2-bis(hydroxyethyl)propionic acid(repeating unit of ABx type)and 2-ethyl-2-(hydroxyethyl)-1,3-propanediol(core molecule)using toluene-sulfonic acid catalyst,and a large amount of terminal hydroxyl were contained in the final synthetic product.The synthesis procedure was a one-step-reaction where stoichiometric amounts crosssponding to each generation were added,The acid value of the synthesized polyesters were measured and infrared spectrum were used to characterize the structure of the synthesized polyesters.This paper studies the effect that the fourth generation hyperbranched polyester and the third generation hyperbranched polyester modified by fatty acid had on nylon 6 and polypropylene and their blend gold.The mechanical properties and rheological properties of the experimental subjects were investigated by different compatibility and different ratio of the agent.When the four generation of polyester were added in Polypropylene,the mechanical properties and melt flow rate of the blends increase.The mechanical properties of the blends did not change but the melt flow rate increased when the hyperbranched polyester modified by three generations of stearic acid added.But for nylon 6,the mechanical properties of the blends decreased slightly when adding the fourth generation hyperbranched polyester,but the melt flow rate increased with the proportion increased,the mechanical properties and melt flow rate of the blends both increased when adding the modified hyperbranched polyester.For nylon 6,tensile and flexural properties of the blends decreased while impact toughness increased,melt flow rate increased first and then decreased with the adding of modified polyester.