Hydrophilic Modification Of PP Non-Woven Fabrics By UV Curing

Polypropylene(PP)nonwoven fabrics can be used as filters in water treatment field owing to its good permeability,low moisture rate,abrasion resistance,acid and alkali resistance,high yield,low cost and high strength,etc.However,there is no hydrophilic groups and microporous in the surface of circular PP fiber,leading to strong inert and hydrophobic of PP non-woven fabric.Furthermore,such hydrophobic PP fabrics is susceptible to pollution in the water treatment process,which is not conducive to membrane flux and separation capacity and restricts its application in water treatment.Therefore,it is an important way to improve the hydrophilic property of PP non-woven fabrics in water treatment field.Hydrophilic modification of poly propylene(PP)nonwoven fabric by UV curing method to cure the UV curable hydrophilic coating on the surface of polypropylene non-woven fabrics and the pore walls.The composition of UV curable coating comprises reactive oligomer(modified acrylic resin),hydrophilic monomer(HEMA,(PEG(400)DA)or TMPTA),photo initiator(Irgacure184)and solvent(ethyl acetate).The UV curable coating solidified onto PP non-woven fabric to improve the hydrophilic property of PP non-woven fabric under UV irradiation.The structure,chemical composition and performance of PP non-woven can be characterized by field emission scanning electron microscopy,infrared spectroscopy,X ray photoelectron spectroscopy,mercury intrusion method,contact angle tester and self-made water flux tester.The specific research contents and conclusions are as follows:1)The hydrophilic layer was formed on the surface of polypropylene non-woven fabric by UV curing and cross linking reaction of single functional hydrophilic monomer HEMA and acrylic resin.The experimental results show that acrylic resin mass fraction was 7%,HEMA mass fraction was 13%,184 mass fraction was 1% and ethyl acetate ethyl acetate was 79%,which are The most suitable hydrophilic modification conditions;the fiber of modified PP nonwoven fabric slightly thickened,small aperture and porosity decreased;the modified PP nonwoven fabric surface introduces a number of hydrophilic groups of-OH and-COO-,the contact angle from 126.47 degrees down to 59.86 degrees and the water flux is 35442L/(m2·h);the modified PP non-woven fabric has good persistence of hydrophilic after 5 times washing;the modified PP non-woven has better anti pollution performance after filtering sediment mixing water;the modified PP non-woven has good resistance to acid and alkali after soaking in acid solution and alkali solution.2)The PEG(400)DA and acrylic resin were used to cure cross linking on polypropylene non-woven fabrics under UV irradiation.The experimental results show that acrylic resin,PEG(400)DA and 184 mass fraction respectively were 7%,13% and 1%,ethyl acetate concentration was 79%,which was the best hydrophilic modification effect;the hydrophilic layer attached to the surface of PP non-woven fabric and pore wall,which lead to the fiber slightly thicker,pore size and porosity smaller;the hydrophilic property of modified PP non-woven was improved because of the introduction of a large number of hydrophilic groups of-C-O-C-and-COO-on PP non-woven surface,the contact angle from 126.47 degrees down to 51.93 degrees,the water flux increased to 36274.13 L/(m2·h);after 5 times of washing,the water flux remained unchanged,hydrophilic good stability;the modified PP non-woven has better anti pollution performance after filtering sediment mixing water;the modified PP non-woven has good resistance to acid and alkali.3)The hydrophilic monomer TMPTA and acrylic resin were cured by UV curing technology to improve the hydrophilic property of PP non-woven fabrics.The experimental results show that the acrylic resin,PEG(400)DA and 184 mass fraction respectively were 7%,13% and 1%,the optimum proportion of ethyl acetate concentration was 79% as hydrophilic modifier,which can make the PP non-woven to achieve the best hydrophilic modification effect;fibers and nodes larger,pore size and porosity of the modified PP non-woven decreased;modified PP non-woven fabric surface introduced a large number of-COO-hydrophilic group,which improved the hydrophilic property of PP non-woven fabric,contact angle from 126.47 down to 54.43 degrees,the water flux increased to 35163.96 L/(m2·h);after 5 times of washing,the modified PP nonwoven water flux remained basically unchanged,which show that the modified PP non-woven fabric has good hydrophilic durability;the anti pollution performance of the modified PP nonwoven is good after filtering sediment mixing water;the modified PP non-woven fabric was soaked in acid and alkali solution and the contact angle was increased slightly,which had good resistance to acid and alkali resistance.