Preparation Of Polysiloxane Modified Polyurethane Acrylate Hybrid Latex And Its Application On Textile Pigment Printing

Pigment printing is a kind of dyeing technology with a long history and it uses adhesives to form a film on the surface of the fabric.It adheres to the colored particles which have no affinity to the fabric to meet the needs of people for fabric coloring.More importantly,it is a clean dyeing technology that almost no uses water with great development potential compared with the coloring technology by molecule dyes.The grade and the quality of painted fabrics are closely related to the properties of the adhesive used and the quality of the adhesives could have greatly influenced the hand feeling,color vividness,and fastness of printed fabrics.However,polyacrylate adhesive,which is widely used at home and abroad,has the disadvantage of heat-adhesion and cold brittleness.The printed fabrics are easy to block the gaps between the fibers,resulting in reduced breathability and poor hand feeling,which greatly affects the quality of printed textile products.In recent years,the preparation of polyurethane acrylate water-based adhesives has become one of the research hotspots.The hybrid latex was prepared by introducing polyurethane into polyacrylate,it can retain the advantages of high gloss and weather resistance of polyacrylate,as well as the advantages of high strength and corrosion resistance of polyurethane.More importantly,it has been shown that the hand feeling,wear resistance,and water resistance of the polyurethane-acrylate hybrid films were significantly improved by organosilicon modification.According to the above research progress,a novel organosilicon-modified polyurethane-acrylic hybrid latex was synthesized by one-step mini-emulsion polymerization to achieve the three complementary advantages and improve the comprehensive performance of pigment printing fabric.First,in the organosilicon modified polyurethane-acrylate hybrid latex system,a series of polyurethane-acrylate hybrid latex(Si-PUA)with different PDMS content were synthesized by minie-mulsion polymerization.Isophorone diisocyanate(IPDI),polycaprolactone(PCL),and hydroxyalkyl terminated polydimethylsiloxane(PDMS)were regarded as polyurethane precursors while styrene(St)and butyl acrylate(BA)were seen as acrylic monomers.Olefin oxysulfonate(DNS-86)was used as an emulsifier,n-hexadecane(HD)as a stabilizer,and azodiisobutyronitrile(AIBN)as initiator.It was systematically studied the properties of the prepared films and it was found that the introduction of silicone improved the water resistance and flexibility of the Si-PUA hybrid films.The water contact angle of the hybrid film was101.7 ° when the mass fraction of PDMS was 20 wt%.The storage modulus of the film was 1092.5 Pa at-55 ℃ while the glass transition temperature was-13.4 ℃.Secondly,the organosilicon modified polyurethane-acrylate/Pigment(Si-PUA/Pigment)hybrid latex was synthesized by the minie-mulsion polymerization method,and the dispersion and morphology of latex were studied by dynamic light scattering(DLS)and transmission electron microscopy(TEM),respectively.Then,the latex was formed into a film,and the hydrophobicity,microstructure,thermal and mechanical properties of the prepared films were measured by using infrared spectroscopy(FT-IR),water contact angle test,differential scanning calorimetry(DSC),dynamic thermomechanical analysis(DMA)and mechanical performance test.The results show that PDMS had good compatibility with polyurethane-acrylate.the water resistance and the elongation at break gradually of the films increased with the increase of PDMS while the breaking strength gradually decreased.When the mass fraction of PDMS was 20 wt%,the water contact angle of Si-PUA/Pigment hybrid films increased 178%,the breaking strength decreased 96%,the elongation at break increased 85%,respectively,compared with the hybrid film without silicone,Finally,the polyester fabric was pigment printed with Si-PUA hybrid latex as a binder by using the traditional pigment printing method.The optimal printing process was determined by changing the baking conditions,the amount of binder,the amount of organic pigment,and the amount of silicone.It was found that with the increase of PDMS content,the softness of the printed fabric increased,the K/S value was more than 10,and the dry and wet rubbing fastness reached 4-5 grades.At the same time,Si-PUA and Si-PUA/pigment hybrid latex were applied to pigment printing of polyester fabric.The friction fastness,K/S value,stiffness,air permeability,and other properties of the printed fabric were investigated,respectively.It is found that with the increase of PDMS content,the air permeability,dry and wet rubbing fastness of the corresponding printed fabric is better,and the handle is softer while the K/S value will decrease slightly.It was worth noting that,based on the comparative study of the above two systems,the silicone has low surface energy which makes it easier to migrate to the surface of the adhesive film during the curing process,resulting in easier movement of the molecular chain in the adhesive film.The use of silicone modified printing coatings could improve the performance of traditional blended printed fabrics.This thesis was designed and prepared a series of Si PUA hybrid latex with good stability and it was revealed the influence of PDMS on the quality of polyurethane acrylate and polyurethane acrylate/pigment hybrid adhesive film.It was found that the fluidity and surface properties of the film are significantly improved.According to the above results,it was realized that the discontinuous covering of fabric surface by adhesive film,the thin overall coating of a single fiber,and the orientation and firm adhesion of the pigment to the fabric fiber.The results of this thesis have instructional significance for improving the coloring quality and wearability of coated fabrics.