Preparation And Properties Of PBS/fGO Composites And PBS-based Hydrophobic Materials

As a kind of novel biodegradable polymer,poly(butylene succinate)(PBS)has wide application prospect in green packaging,biomedical engineering,environmental engineering,ecological agriculture and other fields due to its excellent machinability and biocompatibility.But its performance in the mechanical properties of excellent toughness,lack of strength,limiting its application as engineering materials.As a two-dimensional nanomaterial with excellent properties,graphene can be used to enhance PBS by its nanoscale effect.In the above application areas,such materials are often required to have strong hydrophobicity,so the hydrophobic structure of PBS is also conducive to the development of its application.In view of the above problems,this paper has carried out two aspects of research : Firstly,PBS/fGO composite thin film material was prepared by solution method using functionalized graphene oxide(fGO)as filler,and its mechanical properties,crystallization behavior and thermal stability were investigated.Secondly,the hydrophobic material of PBS was constructed by the method of polymer microphase separation,and its application in oil-water separation was investigated.In order to improve the compatibility of GO with PBS and the dispersibility in PBS,the GO was modified with dodecyldimethylammonium bromide(DDAB)by efficient ion bond effect,Thereby obtaining functionalized graphene oxide(fGO),which can be stably dispersed in chloroform.Then,the PBS/fGO composite films were prepared by solution method,and their structures and properties were characterized.The result of mechanical properties test of the composites shows that 0.1wt% fGO can increase the tensile strength and elongation at break of the composite film by 36% and 31% respectively.However,with the increase of the addition amount,tensile strength and elongation at break show a downward trend;The crystallization behavior analysis showed that the addition of fGO has the effect of inducing heterogeneous nucleation in the crystallization process of the composites,However,due to the hindered effect exhibited by the modified fGO,the rearrangement of the PBS molecular chain during the crystallization process is restricted,so that the crystallization temperature of the composite increases and the crystallinity decreases.The thermal stability analysis showed that the addition of fGO had no significant effect on the thermal stability of the PBS composites.Based on the principle of polymer microphase separation,the preparation process of biodegradable PBS film with strong hydrophobicity was designed with chloroform as solvent,ethanol,n-butanol,ethyl acetate and butyl acetate as non-solvent.The effects of PBS concentration and non-solvent content on the wettability,crystallinity,adhesion and surface morphology of the prepared films were investigated.The results show that all kinds of the non-solvents can significant increase the static contact angle of PBS hydrophobic film,have reached a maximum of 142.5°,which is nearly 60° higher than that of the untreated PBS.The adherence of the prepared highly hydrophobic PBS surface to water droplets was higher than 100 μN and reached a maximum of 248 μN,all of which showed high adhesion characteristic.This is mainly because the phase separation enables the film surface to building the micron-nanometer structure with different shape,which is determined by the pinning effect and capillary effect of the fine micrometer-nanometer multi-stage structure in contact with the water droplets,and it is consistent with the Cassie infiltration model.The static contact angle of the hydrophobic surface affected by the concentration of PBS to a certain extent,which increases with the amount of non-solvent.This is mainly attributed to the fact that the difference of micro-nanostructures constructed by phase separation when the PBS concentration and the solvent amount change.The crystallinity of the obtained hydrophobic film is greatly improved compared with that of untreated PBS,which is positively correlated with its hydrophobicity.The greater the crystallinity of the material is,the greater the contact angle would be.At the same time,three-dimensional PBS-based hydrophobic materials were prepared by solvent-non-solvent method,and the oil-water separation effect was explored.The hydrophobic material produced has excellent hydrophobicity and lipophilicity,and its ability to absorb oil and organic solvent can reach 5 to 9 times of its weight,which indicates that the material has a certain application prospect in the field of oil and water separation.