Preparation And Study Of PTFE/TPU Antibacterial Membranes With Rebound Elasticity

The blend multi-microporous structure of membranes with rebound elasticity are prepared by introducing thermoplastic polyurethane (TPU) into polytetrafluoroethylene(PTFE), which improves the rebound elasticity of PTFE biaxial stretching membrane after stressed. Addition of nano-SiO2 treated by coupling agent is propitious that TPU disperse into PTFE equably, consequently the rebound elasticity of membrane is enhanced. The composition of the blend membrane and the biaxial stretching rate have some effect on the rebound elasticity. The results of scanning electron microscopy (SEM) show the factor above-mentioned that effect the microstructure is the reason of the different rebound elasticity. The SEM also shows the combine property between TPU and PTFE.Multi-microporous structures of biaxial stretching PTFE/TPU blend membranes are observed by Scanning electron microscopy (SEM) micrographs. The PTFE and of the membranes are stretched into small fibers, while TPU could adhere tht PTFE fibers equably.The PTFE fibers were stretched from the raw fibers of the PTFE particles, and the TPU attached to the PTFE is also stretched into coat. PTFE fibers are stretched from the "knots", and constructed microporous structures with the knots and the fibers, and microporous present the space net structure. Rate of biaxial stretching has a great effect on size and shape of microporous.Differential scanning calorimetry (DSC) showed that introduction of TPU could decrease the initial melt temperature and the melt enthalpy. This shows that the addition of TPU has effect on the crystal performance, and the TPU has a good distribution in PTFE. The initial melt temperature also decrease by the addition of quantificational nano-silica dioxide, however the initial melt temperature will reascent over 3%.IR is proceed on the membrane afer the addition of nano-silica dioxide, and it shows that absorbtion peaks appare in the range between 3000 and 3200, which is the librate wave range of hydrogen bond between molecules. It shows that the hydrogen bond effect between PTFE matrix and nano-silica dioxide particle presents with the addition of nano-silica dioxide, which enhances the rigidity, tensile strength and rebound elasticity. But nano-silica dioxide will destroy the continuity of PTFE when over certain content, which decreases the mechanics performance.Rebound elasticity test is proceed on the biaxial stretching PTFE/TPU blend membranes. Results showed that the rebound elasticity of PTFE membranes is improved with the increasing of TPU. It is discussed the effect of nano-silica dioxide and biaxial stretching on rebound elasticity Mechanics performance of PTFE/TPU blend membance has been tested, and the effect of compose and the content of nano-silica dioxide and assist agent on the tensile strength and tensile elongation.The rigidity of polytetrafluoroethylene product is reinforced with the addition of the nano-silica dioxide particle, however, the tensile elongation of PTFE membranes decreases with the content of nano-silica dioxide increasing. At the same time, polytetrafluoroethylene will converse from plasticity to brittleness.The moisture permeable performance of biaxial stretching PTFE/TPU membranes was studied. Result shows the addition of TPU rarely effects moisture permeable performance of polytetrafluoroethylene membrane, so the high moisture permeable performance of the polytetrafluoroethylene membrane is preserved.Porosity and porosity distribution have been tested by the way of hydrargyrum pression, and the effect of biaxial stretching on the porosity and porosity distribution has been discussed.There is a great difference between TPU and PTFE on hydraphile performance. The contact angle of membrance has been proceed, and the result shows that the introduction of TPU could improve the hydraphile performance of PTFE.Nano- TiO₂ and nano-Ag particle are introduced into the PTFE/TPU blend membrance, which shows membrance has a great antibacterial effect on the colibacillus.