Dimensional Stability And Structure Study Of Ultra-high Molecular Weight Polyethylene Films

In order to improve the shrinkage performance and dimensional stability of membrane products,UHMWPE/SiO₂ hollow composite membrane was prepared by using UHMWPE as raw material,mineral oil as diluent,SiO₂ as additive,copper wire and polyester yarn as supporting materials,and TIPS method was used to prepare reinforced UHMWPE/SiO₂ hollow composite membrane The shrinkage,permeability,mechanical properties,antibacterial properties and anti-pollution properties were studied.Firstly,the effect of the amount of SiO₂ on the structure and properties of the blend membrane was discussed.In order to study the effect of SiO₂ on the shrinkage of the blend membrane,the shrinkage of the blend membrane was characterized by measuring the length and diameter changes during the extraction process.It was found that the addition of SiO₂ can improve the shrinkage of the membrane.The crystallization nucleation point of the system was increased by SiO₂,and the network structure was formed between the crystal aggregate and UHMWPE fibril.In addition,the orientation and crystallinity of the blend membrane were tested by sonic orientation and X-ray diffraction.It was found that the orientation and crystallinity of the blend membrane affected the shrinkage of the blend membrane.The micro morphology of the blend membrane was observed by SEM,and the porosity,flux,contact angle and mechanical properties were tested.It was found that when the ratio of SiO₂/UHMWPE was 2wt%:20wt%,the contact angle was 128.72°,the porosity was 65.86%,the water flux was501.48 L·m^-2·h^-1,the air flux was 3761.2 L·m^-2·h^-1,and the tensile strength increased by 53.25%when SiO₂ was added.On this basis,the reinforced UHMWPE/SiO₂ hollow composite membrane was prepared by changing the support materials,and the influence of different support materials on the structure and performance of the membrane was explored.It is found that the shrinkage of UHMWPE/SiO₂ hollow composite membrane can be significantly improved by copper and polyester yarns.The shrinkage of length,diameter of Cu/UHMWPE/SiO₂ hollow composite membrane can be reduced by 80%,50%respectively.The dimensional stability was greatly improved.The decrease of shrinkage makes the membrane pore structure stable and the membrane pore is not easy to shrink,which is beneficial to improve the permeability of membrane.At the same time,Cu/UHMWPE/SiO₂ composite membrane has excellent antibacterial and anti-pollution properties.