Preparation Of Bio-based Polyesters With Shape Memory And Construction Of Surface Micro/nano-structures

Shape memory polymer(SMP),which is able to take on reversible transformations from permanent shapes to temporary shapes,has demonstrated promising potentials in a wide variety of fields,such as tissue engineering and wearable devices.However,most SMPs suffer from low elongation at break,low fracture strength as well as non-degradable owing to their inherent structure and composition,leading to weak mechanical property and limiting its practical applications.Therefore,the preparation of inherent bio-based SMPs with recoverable and high strain will be urgent issue.In addition,the surface wettability of polymer can be regulated by the construction of micro/nano-structures,further applied to application in some special fields,such as directional transport of droplets and separation of oil/water.In view of the above problems,this work uses melt blending and separated-nanophase-assisted heterogeneous polymerization strategy to prepare PBS/PDC composites and PBDC polymers,respectively,while the bio-based poly(citric acid-decanediol)(PDC)is synthesized by citric acid(CA)and 1,10-decanediol(DD)as the matrix.In addition,their chemical structures,mechanical properties and memory properties are investigated.Next,the micro/nano-structures of PBDC polymer and PLA nonwoven filter surface is constructed by the bio-template and non-solvent assisted phase separation method,respectively,and the interrelation of surface morphology with wettability and practical applications are also explored.The preparations and properties of PBS/PDC composites and PBDC polymers.Firstly,PBS/PDC composites are prepared by melting method,and the effects of PBS content on the properties of composites are studied.The results show that PBS/PDC composite not only has good compatibility and phase transition temperature of-3.3 ?,but also has deformation of 300%and reversible shape memory effect of 98%when the addition amount of PBS is 10 wt%.In addition,PBDC polymers are also prepared by separated-nanophase-assisted heterogeneous polymerization strategy,and the effects of different molar ratios of 1,4-butanediol(BD)on the structure and properties of PBDC polymers are investigated.When themolar ratio of BD is 7%,the synthesized PBDC polymer exhibits high gel fractions of 86%and the phase transition temperature of 4.2 ?.Moreover,its elongation at break is above 750%,the shape fixing rate and recovery rate maintain at 99%and 98%,respectively,and the shapes of 2D and 3D can rapid response around 20 seconds,indicating its fast thermal response characteristics.The construction of micro/nano-structures on PBDC polymer surface and regulation of wettability.In this work,PDMS is used as a soft template to transfer the micro/nanostructure on the back of bamboo leaves to the surface of PBDC polymer.It shows that the micro/nano-structures array formed on the surface of PBDC polymer has good shape memory properties.In addition,stearic acid(SA)is used to modify the surface of PBDC polymer,and the adjustability of surface wettability is investigated.Finally,the water contact angle of PBDC polymer surface can be reversibly tuned from 136° to 48°,and the PBDC polymer is applied to the directional collection of water.The construction of micro/nano-structures on PLA nonwoven filter surface and regulation of wettability.In this work,PLA nonwoven filter with micro/nano-structures is prepared via non-solvent(ethanol)assisted phase separation method while the PLA solution(50 mg/ml)is used as coating solution.The result shows that the water contact angle on PLA nonwoven filter surface can be tuned from 120° to 151°.In addition,the application of PLA nonwoven filter in oil/water separation is also investigated.After 20 cycles,the separation efficiency of PLA nonwoven filter is still above 95%,and PLA nonwoven filter has strong corrosion resistance and chemical stability,which indicate that it has excellent application value in the treatment of oily wastewaters.In this study,the bio-based PBDC shape memory polymer with high deformation and prepared superhydrophobic PLA nonwoven filter not only can avoid the secondary pollution during the post-processing,but also its excellent shape memory property and surface wettability will further expand the application field.In addition,the exploitation of separated-nanophase-assisted heterogeneous polymerization strategy will provides a new idea for the preparation of materials with high-deformation.