The Study On Preparation And Properties Of Shpae Memory Composites Based On Polymers

Shape memory polymer is one of the important branches of smart materials.Its most important feature is that it can remember a certain initial shape,can be given a certain temporary shape under certain conditions,and can be stimulated appropriately(such as temperature,solvent,pH,light,electromagnetic field,etc.)return to its original shape.Compared with traditional shape memory materials,shape memory polymer materials usually have the characteristics of high processability,diversified structures,light weight,high deformation quantities,high recovery and low residual strains.Those grant SMPs great potentials on applications such as aerospace,intelligent textiles,selfhealing materials,high-performance sensors.As a kind of bio-based polymer material,shape memory materials are one of the important development approaches for TPI.In this paper,The effect of filler on the properties of TPI based shape memory materials,the effect of blending ratio,vulcanization system and compatibilizer on the properties of TPI/PCL shape memory composites,the effect of blending ratio on the properties of TPI/MCC and TPI/PEO shape memory composites were studied,and the vulcanization properties,crystallization properties,mechanical properties,crosslinking properties,shape memory properties and relationships between the microscopic phase structure and the macroscopic properties were systematic analyzed.The research content of this paper was exhibited as follows:First,we explored the effects of zinc methacrylate(ZDMA)and carbon nanotubes(CNTs)on the mechanical properties,crystallization,shape memory performance and other properties of the TPI(Trans-1,4-polyisoprene)matrix.The results showed that when ZDMA was directly added,the mechanical strength of the system was improved.However,the mechanical properties of TPI system showed a downward trend with increment of DCP(Dicumyl peroxide)dosage.At the same time,the crystallinity of the system was inversely proportional to the DCP dosage.When DCP dosage was 0.2 phr,the TPI system had the best shape memory performance.When ZDMA was generated in situ,the in-situ formation of ZDMA can also effectively improved the mechanical strength of the system.However,the mechanical properties of the TPI system decreased as increment of DCP dosage.The crystallinity change of the system was inversely proportional to DCP dosage.When DCP dosage was 0.1 phr,the system had the best shape memory performance.Additions of CNTs could significantly improve the mechanical properties of the composites,while maintaining the excellent shape memory performance of the system.The crystallinity change of the system was proportional to DCP dosage.Best comprehensive performance of composites was maintained when CNTs dosage was 1 phr.Secondly,we explored the effects of vulcanizing agent,compatibilizer and blending ratio on the mechanical properties,crystallization and shape memory performance of TPI/PCL(Polycaprolactone)matrix.When blending ratio of PCL/TPI was fixed at 80/20,the tensile strength and elongation at break of blends was improved as increase of BPO dosage.While tear strength,100% modulus and crystallinity of of blends showed opposite trendency.The shape memory performance of the composites was optimal when the BPO(Dibenzoyl peroxide)dosage was 2 phr.The addition of the compatibilizer PCO(Polycyclooctene)could effectively improve the compatibility of the two components,and the mechanical properties and shape memory properties of the composites were improved overall.The results showed that the mechanical properties of the composites decreased with the decrease of PCL dosage.The change of crystallinity of the system showed a peak shape with the PCL dosage.When the ratio of PCL/TPI was 80/20,the composites had the best shape memory properties.Finally,we explored the effects of blending ratio on the mechanical properties,crystallization,and double-stimulus shape memory performance of TPI/MCC(Microcrystalline cellulose)and TPI/PEO(Polyethylene oxide)double-stimulated corresponding matrix.The results showed that in the TPI/MCC system,DCP was used as the vulcanization system.As the increase of MCC,which possessed hydrophilic properties,the mechanical properties of the composites was decreased while hydrophilicity was improved,which granted blends with potentials on water/heat dualstimuli shape memory performance.In the TPI/PEO system,with the increase of waterabsorbing material PEO dosage,the mechanical properties of the composites were kept relatively good,and the excellent water absorption performance was imparted,so that the composites had good water/heat double response memory performance.