Synthesis And Molecular Simulation Of Double Network Hydrogel Based On PASP Hydrogel

Poly (aspartic acid) (PASP) is a kind of environmentally friendly polymer with excellent biocompatibility, water-absorbing quality and biodegradability, which is polymerized by amino acid monomer. Therefore it is widely used in many fields, such as agriculture, hygienic products, tissue engineering and drug delivery and it has incomparable advantages from the aspect of environmental friendliness compared with the commonly used polyacrylic resin. However, the applications in these fields of poly (aspartic acid) hydrogel prepared by existing process in our laboratory are restricted for its weak mechanical strength, poor stability and poor salt resistance in saline water.In order to improve the mechanical strength and stability of PASP, we combine the technique of double network hydrogel with the existing synthetic process of PASP hydrogel in our laboratory. This method can also reduce the cost of hydrogel. At the same time, in this study, atomistic MD simulations are performed to investigate the effect of water content on the equilibrium structure and the water transport properties of the Poly (aspartic acid)-Poly (acrylic acid) double network hydrogel.In this task, the preparation process of double network hydrogel is improved to be better applied in baby diapers by introducing the third inorganic network with high salt resistance. We also investigate its rapid swelling ratio in saline water, swelling ratio under pressure, rheological properties, degradability and cell toxicity. Experimental results show that the hydrogel can meet the national standard of water absorbing resin for diapers, with water absorbency under pressure getting to 32 g-g-1 and rapid water absorbency of 76 g·g-1. Furthermore, this hydrogel without toxicity has excellent mechanical properties and degradability with degradation rate in 96 h of 56%.Finally, we try to fully abandon the use of polyacrylic acid network which is not easy to degrade and try to use the environmental inorganic silicon network to make a kind of PASP-SiO2 double network hydrogel. This method has simple steps and completely devoid the use of polyacrylic acid which makes the green environmental protection property of hydrogel more persuasive. In addition, water absorbency of the hydrogel can meet the national standard requirements. The mechanical strength and thermal degradation of hydrogel have improved obviously.