Preparation,structure And Properties Of Polymer Materials With Antifouling And Slow-Release Properties

With the development of society and the progress of science and technology,polymer materials play an increasingly large and irreplaceable role in the field of biomedicine.Polymer materials with antifouling,slow-release and targeting functions have been the forefront and hotspot of polymer science and polymer material science.In this dissertation,the surface of polymer materials with hydrophilic and superhydrophobic properties and PAAm/diatomite composite hydrogel with slow-release property were prepared.And mainly investigated the influence of the chemical composition and molecular chain conformation on the antifouling property of polymer materials surface,and to lay a foundation for the next research on the surface hydrogel of SEBS,the mechanical properties and slow-release function of the PAAm hydrogel were studied further.And the following results are obtained:1.Effect of looped conformation of PEG modified SEBS surface on blood compatibilityBy attaching polydopamine to the poly(styrene-b-(ethylene-co-butylene)-b-styrene)(SEBS)surface and further reacting with the terminated mercapto groups of polyethylene glycol(PEG),the linear and looped conformation of PEGs were successfully constructed on the SEBS surface by using PEG with mercapto groups at one end and both ends.It was found that after the surface modification of SEBS by dopamine and PEG,the amounts of protein adsorption and platelet adhesion decreased significantly.Further studies showed that the PEG modified surface with looped conformation had better blood compatibility due to its higher elasticity and reduced the contaction and binding with proteins.2.Construction of antifouling and bactericidal surface based on lysine derivativesAccording to the theory of water barrier and the mechanism of killing bacteria of antibacterial peptide,A,B two monomers(LysAAm-QAC and LysAAm-OBzl)were synthesized by the introduction of quaternary ammonium cationic(QAC)and hydrophobic benzyl acetate(OBzl)onto the hydrophilic monomer(LysAAm),by modifying the amino and carboxyl respectively.Firstly,A and B monomers were grafted onto the surface of the silicon wafer in proportion,and their antifouling and bactericidal properties were studied by means of laser confocal microscopy(CLSM)and quartz crystal microbalance(QCM-D).Results show that the surface with the A/B ratio of 3/7 had excellent resistance to protein adsorption,platelet and red cell adhesion and resistance to bacterial adhesion and bactericidal properties,and it was found that the antifouling performance mainly relied on the hydrophilicity(43.6°)provided by lysine,the main chain structure of the modified surface,and the high surface coverage ratio of the two monomers(91.49%),and the bactericidal performance mainly depended on the quaternary ammonium cation and the hydrophobic OBzl,and the bactericidal performance improved with the increase of hydrophobic OBzl content.By introducing bactericidal components QAC and OBzl into LysAAm,a hydrophilic monomer with antifouling properties,and optimizing the grafting ratio of LysAAm-QAC and LysAAm-OBzl monomers,the surfaces with antifouling and antibacterial properties can be obtained.On this basis,the antifouling and bactericidal layer of lysine derivatives was successfully constructed on the surface of SEBS.3.Preparation of superhydrophobic SEBS with antifouling and NBP adsorption resistance propertiesInspired by the "lotus leaf phenomenon",using xylene/decyl alcohol as good/bad solvent to induced phase separation of SEBS,and adding 1 phr palm wax with low surface energy under the condition of 60? annealing treatment,SEBS-SHB-1-60? sample with rough surface with the accumulation of fold structure microspheres was prepared,and the structure and properties were studied.It was found that the superhydrophobic surface with low surface energy wax and the rough structure at the same time,not only had good antifouling property such as platelet and red blood cell adhesion resistance,but also had good NBP adsorption resistance performance that 1 h adsorption of NBP concentrate was reduced from the original 63.8%to 10%.It provides an effective method to solve the problem of NBP adsorption which has troubled clinical application.4.Mechanical and slow-released property of poly(acrylamide)hydrogel reinforced by diatmitePAAm/diatomite composite hydrogels were synthesized by in-situ radical polymerization.The study found that the mechanical properties of the composite hydrogel can be improved effectively with 8 phr diatomite and the good hydrophilicity of the composite hydrogel with low phr diatomite filling have certain mouse fibroblast and blood cell adhesion resistance properties.The model drug carbendazim was added to the PAAm/diatomite composite hydrogel,which had a good slow-release function.The release time of 50%carbendazim was up to 4 days,and the molecular diffusion mechanism of carbendazim was non-Fick diffusion.