The Research On The Properties Of Hydrophobic Association Hydrogels Prepared By Porous Starch

Hydrophobic association hydrogels have attracted wide attention from many scholars and they are widely used in intelligent materials,such as tissue engineering scaffolds,drug carriers,wound dressings and biosensors owing to their excellent mechanical properties.However,traditional hydrogels possess low mechanical properties and undergo irreversible deformation after fracture,which greatly limit their wide applications of hydrogels to some extent.Therefore,the preparation of hydrogels with high mechanical properties is still a hot topic of current research.Interpenetrating networks are formed by two or more polymer networks interpenetrating each other to form polymers with special properties.In the hydrogel system,the two polymers form a network alone,and the two networks are independent and do not affect each other.Since the two networks pass through each other and form synergistic effect,which endow the hydrogels with excellent mechanical properties.In this paper,the method of emulsion cross-linking was used to synthesize porous starch using natural starch.The starch is added to the system of hydrophobic association hydrogels prepared from lauryl methacrylate.Since in the process of preparing porous starch,a method of emulsion crosslinking is employed,and a crosslinking agent is added to crosslink the starch to form a network.Lauryl methacrylate is a kind of hydrophobic monomer,micelles are formed by the action of the surfactant during the preparation of the hydrogel,and the main monomer acrylamide is polymerized to form a hydrophobic association network.In addition,a large number of pore structures exist on the surface of the porous starch,and the chains of acrylamide can pass through the pores,thereby forming an interpenetrating network hydrogel.We performed tensile and rheological tests on pure hydrophobic association hydrogels,natural starch hydrogels and porous starch hydrophobic association hydrogels to determine the toughening mechanism,and utilized infrared spectroscopy and scanning electron microscopy to determine the structure of the porous starch.The hydrophobic association hydrogel prepared from porous starch has excellent mechanical properties,a fracture stress of 0.929 MPa,a fracture strain of 2733%,which is about three times that of pure hydrophobic association hydrogel.This is because interpenetrating network hydrogels are formed by the cross-linked porous starch and hydrophobic association network coexisting in the hydrogel system.