Preparation And Properties Of Polyvinyl Alcohol/Organic Silicon Hydrogels With High Strength

Hydrogels are a class of hydrophilic polymers having a three-dimensional network structure formed by cross-linking by chemical/physical interactions.Hydrogels with unique three-dimensional network structure are widely used in bioengineering and medicine due to their water absorption and biocompatibility.However,due to poor mechanical properties,the current applications of hydrogels are still extremely limited.Among them,polyvinyl alcohol(PVA)hydrogel has attracted extensive attention due to its structure similar to cytoplasmic matrix.It is generally believed that the mechanical properties of pure PVA hydrogel is poor,and their practical applications are still greatly limited.Aiming at this problem,this work improved the mechanical properties of PVA hydrogel by using silicone composite method and studied its hydrophilic properties and biocompatibility,making them biomedical materials with practical value.Firstly,the preparation method of Ms-PDMS/PVA composite hydrogel was developed by in-situ polymerization in PVA solution to form polydimethylsiloxane(PDMS)elastomer microspheres(Ms-PDMS),and uniform recombination between PDMS two incompatible materials was skillfully solved.The results show that the MsPDMS/PVA composite hydrogel has a three-dimensional network structure,and the PDMS microspheres(5-10 ?m)with regular shape were uniformly dispersed in the PVA hydrogel without agglomeration;the introduction of Ms-PDMS have no adverse effect on the crystallinity of PVA hydrogels;Ms-PDMS/PVA composite hydrogels have significantly improved compression properties(compressive elastic modulus ~4.5 MPa)while maintaining high water content(>80%).However,due to the absence of interaction between the Ms-PDMS and the PVA,the tensile properties of the composite hydrogel were not significantly improved.In summary,this method provided a new idea for the composite problem of two incompatible materials,and designed a new way to improve the mechanical properties of hydrogel.Secondly,based on the research of Ms-PDMS/PVA composite hydrogel,watersoluble silicone oil was further introduced to enhance the interaction between hydrophilic PVA and hydrophobic Ms-PDMS,thereby improving its tensile properties.The results show that the hydrogel after introduction of water-soluble silicone oil still has a good three-dimensional network structure,and Ms-PDMS can be uniformly embedded in the hydrogel matrix;the tensile properties of the composite hydrogel are significantly improved compared with the pure PVA hydrogel(tensile strength ~ 0.47 MPa),and the hydrogel has good hydrophilic properties and biocompatibility.This work significantly improved the tensile strength of PVA hydrogel on the basis of the first part of the content,and provided the research idea of using "amphiphilic" molecules as a linker to improve the performance of the composite hydrogel.Thirdly,inspired by the above-mentioned water-soluble silicone oil,?-amino propyltriethoxysilane(KH550)can be hydrolyzed to form silanol,and spontaneously polycondensed to form organo-siloxane(containing-OH and-NH2).The hydrolyzed product of KH550 was introduced into PVA hydrogel to improve its mechanical properties.The results show that the organic silicone composite hydrogels have good three-dimensional network structure;its tensile properties are improved by 12 times and the compressive properties is also improved by nearly 5 times compared with the PVA hydrogel.In addition,cell viability assay showed that the hydrogel has good biocompatibility.The silicone-polyvinyl alcohol copolymer interpenetrating network hydrogel based on KH550 hydrolysis still has excellent mechanical strength and biocompatibility while maintaining high water content(>82%).In summary,the mechanical properties of PVA hydrogels have been significantly improved by the organosilicon composite method,and the prepared MsPDMS/PVA/silicone oil composite hydrogel and the organic silicon-polyvinyl alcohol copolymer network hydrogel have good three-dimensional network structure,high water content,and excellent mechanical properties and biocompatibility.It can be used as a biomaterial in bioengineering and medicine field.