Preparation Of Poly(Butyl Acrylate-acrylonitrile) Latex Microspheres And Their Effect On Hydrogel Properties

Hydrogels are non-water soluble polymeric materials with a three-dimensional crosslinking network structure capable of swelling and trapping a large amount of water.To date,hydrogels have received considerable interest in many fields due to their unique properties,including biomedicine,tissue engineering,medical equipment,sensors,artificial intelligence and so on.However,conventional hydrogels exhibit poor mechanical properties due to their heterogeneous network structure,resulting in a limitation of their application.Consequently,in order to strengthen and expand the application range of hydrogels,some studies have focused on developing new mechanisms to strengthen hydrogels,including topology hydrogels,nanoparticle composite hydrogels,double network(DN)hydrogels,tetra-PEG hydrogels,ionically cross-linked hydrogels,hydrophobic association hydrogels,macromolecular microspheres composite(MMs)hydrogels and so on.The MMs hydrogel that is as the one of these high strength hydrogels hasn't been further studied,and some previous researches mainly concentrated on the method of crosslinking between microspheres and matrix polymer chains.This paper started from the emulsion microspheres and was to synthetize different kinds of emulsion microspheres through the design for microspheres structure.Then these emulsion microspheres were introduced into the hydrogel system to further analyze the emulsion microspheres' important impact on properties of hydrogels.The main research contents are following:The acrylonitrile monomers(AN)were introduced into the polyacrylate latex microspheres(PBA LMs),and that was to use isomolar volume of acrylonitrile monomers and butyl acrylate monomers to synthesize single dispersible poly(butyl acrylateacrylonitrile)latex microspheres(P(BA-AN)LMs)through the traditional emulsion polymerization.Because of hydrophobic interaction,the hexadecyl methacrylate(HMA),which was stabilized by surfactant sodium dodecyl sulfate(SDS),would be absorbed to the surface of P(BA-AN)LMs and the free radical copolymerization of HMA and acrylamide(AAm)occurred under the action of REDOX initiator to form the hydrogel(P(HMA-AAm)-P(BA-AN)hydrogel).The P(BA-AN)LMs acted as crosslinking centers for hydrophobic association to strengthen the P(HMA-AAm)-P(BA-AN)hydrogel.As a comparison,we used the same method to synthesize the single dispersible PBA LMs with similar size and P(HMA-AAm)-PBA hydrogel strengthened by the PBA LMs.By relevant tests,it was found that P(BA-AN)LMs can have a better toughening effect,which resulted from the dipoledipole interaction between nitrile groups in the inside of P(BA-AN)LMs and it made the entanglement of internal polymer chains of P(BA-AN)LMs more closer.Consequently,P(BA-AN)LMs,acting as the vital crosslinking centers for hydrophobic association in the system of hydrogel,can have an immeasurable effect on the properties of hydrogels.