Research On The Heating And Lighting Resistance Of Coated Covering Fabrics

Coated covering fabrics occupy the leading position in coated fabrics, and they arerainproof cover supplies of the station, port, open warehouse and goods protective equipments ofcar, railway, or shipping. With the rapid development of national economy and the quickening ofthe process of industrialization, coated covering fabrics are widely used in various sectors of thesociety, such as agriculture, industry, transportation, etc. Coated covering fabrics often exposedto the environment, owing to sunshine, air, water and stress, etc, the aging phenomenon is easyto occur with the extension of time, making the material lose its original function and shorten theuse life. Therefore, studying on the weatherability of coated covering fabrics can provide sometheory and experiment reference for correctly assessing their aging resistance, so as to betterforecasting service life of the products.In this paper, temperature and ultraviolet ray are simulated in the laboratory, and thenrespectively discuss and analysis the physical chemistry performance change of polyacrylic acidester （PA）, polyurethane （PU） and polyvinyl chloride （PVC） coated covering fabrics. Maincontents of research are as follows:（1） The infrared spectrum, thermal stability, mechanical properties and wear resistance ofcoated covering fabrics were tested and analysised, the results show that: PA coating containsC-H, C=O, COO^-1, C-O and other features absorption peaks, PU coating contains C-H, C=O,C=C, C-O-C and so on, PVC coating contains C-H, C=O, C-C, C-Cl, etc; Btween0²00℃,the weightlessness rate of PA、PU、PVC coated fabrics is small, which is caused by a smallamount of coating agent. When the temperature reaches495℃,the weightlessness rate of3kinds of coated covering fabrics is all around50%; Three kinds of coated covering fabrics allhave good mechanical performance, among them, PVC coating is superior to others; The frictionlosses of the fabrics increase with the increasing of rub numbers, but the loss rate decrease gradually.（2） Choosing heat treatment temperature and time for two aging factors, we did anaccelerated aging to3kinds of coating covering fabrics. The results of the study show that:Three coating agent on the fabric covering all reduced in different degree, and PVC coated levelchange was more obvious for appearing cracks; With the increase of heat treatment temperature,the characteristic absorption peaks of PVC became smaller and disappeared in the end, whichexplained by CH₂, C=O ruptured and led to polymer degradation; With the extension of time,the weight of3kinds of fabrics became lighter, among them, the quality loss of PVC coating wasparticularly obvious, which was caused by the volatilization of large amounts of DOP; With theincrease of temperature and time, the chromatism of coating increased, and the change of PVCwas particularly evident due to the thermal oxygen degradation products, which were typicalchromophore groups; With the increase of heat treatment temperature and time, the strength of3kinds of coated covering fabrics decreased in different degree, when the heat treatmenttemperature of85℃and time of3d in the aging process, PVC coated covering fabric still hadhigher strength.（3） Choosing ultraviolet intensity and time for two aging factors, we did an acceleratedaging to3kinds of coating covering fabrics. The results of the study show that: PA coatingappeared corrosion hole, PU coating appeared cracks and part of the yarns completely fractured,and PVC coating surface groove totally disappeared, simultaneously with crack appeared; Underthe irradiation of ultraviolet ray, PA coating generated hydrogen peroxide role and peroxide byreacting with oxygen, PU generated two degradation, respectively for C-N key and C-O keyfracture, PVC released much HCl in the process of aging, and volatilisation of plasticizer madeabsorption peaks intensity decreased; In the process of ultraviolet radiation, the chromatismbecame large, and the change of PVC coating was particularly evident due to much （CH=CH）_nlong chain produced in the aging process; With the increase of ultraviolet intensity and time, thestrength of3kinds of coated covering fabrics decreased in different degree, when ultravioletintensity of16000μW/cm²and time of0.5h in the aging process, PVC coated covering fabric stillhad higher strength. Meanwhile, the mechanical properties of3kinds of fabrics were obviouslypositive related under the condition of changing ultraviolet intensity or time.