Study On Hygrothermal Aging And Self-cleaning Properties Of High-strength PET Fabric/PVC Flexible Composites

As a new type of textile structure flexible composites,high-strength polyester fabric/polyvinyl chloride（PET/PVC）flexible composites has the advantages of light weight,high strength,good flexibility and excellent processing performance,etc.It is widely used in outdoor construction,especially in the field of canopy materials.However,the aging resistance and anti-fouling properties of composites are usually poor due to the influence of water vapor wicking and plasticizer migration in hot and humid environments,while the long-term wicking will destroy the interface of composites,resulting in the degradation of mechanical properties of composites and greatly shortening its service life.Therefore,in this paper,firstly,the anti-wicking F-PET/PVC flexible composites were prepared by hydrophobic modification of PET fabric surface with anti-wicking agent,and its hygrothermal aging properties were investigated.Then,the fluorinated HNTs@Si O₂（FHS）hybrid fillers were further prepared by a combination of sol-gel and fluorination modification.After mixing with PVDF dispersion,the PVDF/FHS superhydrophobic coating was successfully constructed on the surface of F-PET/PVC composites by spraying method.Finally,the superhydrophobic self-cleaning properties and durability of the coating was characterized and analyzed.The main research contents of this paper are as follows:（1）PET fabrics were hydrophobically modified by fluorine-free and fluorine-containing anti-wicking agent,and the water repellency and wicking properties of the modified fabrics were tested.The results show that the fluorine-containing anti-wicking agent has better waterproof performance than the fluorine-free anti-wicking agent,and the fluorine-containing anti-wicking agent F1 has better anti-wicking performance than F2.When the concentration of F1 was 20 g/L,the water contact angle of the fabric surface reached 114.5°,and the warp wicking height was reduced to below 10 mm.（2）F-PET/PVC flexible composites were prepared by laminating PVC slurry with F-PET fabric by the coating method.The results showed that the hydrophobicity of the PET fabric was significantly improved after the anti-wicking modification,the wicking height of the F-PET/PVC flexible composites decreased by 94.29%and the peeling strength decreased by 15.87%compared with the unmodified sample when the plasticizer content was 60 phr.After hygrothermal aging,the peeling strength and tensile strength loss rate of the composites were reduced by 4.33%and 3.13%,respectively,compared with the unmodified samples,showing the better hygrothermal aging resistance of F-PET/PVC.（3）The superhydrophobic FHS hybrid fillers were prepared using tetraethyl orthosilicate（TEOS）as the precursor and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane（PFDTES）as the modifier by sol-gel method for in-situ growth of fluorinated nano-Si O₂on the surface of HNTs.Then,a superhydrophobic self-cleaning PVDF/FHS coating was constructed on the surface of F-PET/PVC composites by one-step spraying method using PVDF as the coating matrix.The results showed that the low surface energy fluorinated modified nano-Si O₂ was successfully loaded on the surface of HNTs.When the PVDF content is 10%and the FHS content is 3%,the water contact angle of the coating reaches151.7°,and shows excellent durability and self-cleaning performance.