Preparation And Application Of Coating Adhesive With Flexible Interpenetrating Polymer Network

With its low-carbon, environmental-friendly and simple process, coating printing has been widely used in dyeing of cotton. However, rubbing fastness of dyeing fabric is dissatisfied, and the hand feeling of dyeing fabric is hard. The main factor which determines the coating quality is the performance of coating dyeing adhesive. Interpenetrating polymer network is composed of two or more kinds of polymer blends, the molecular chain interconnected, and at least one polymer chain formed cross-linked network structure with chemical bonds. Because of interpenetrating polymer network structure characteristics and interconnected phases, it also has some unique mechanical properties. Therefore, using interpenetrating polymer network technology has important significance to improve performance of adhesive.According to the requirements of the adhesive coating printing, polyacrylate microemulsion latex with the first network structure was first prepared. This emulsion can cure to film at low temperature, which can be applied to fabric printing and dyeing. As a result, the soft fabric was obtained. To solve the first network film's problem of low friction fastness, adding linear macromolecules of PVA and glyoxal cross-linking monomer composition of the second component was designed. PVA and glyoxal cross-link between each other, and interpenetrate with the first network, therefore, interpenetrating polymer network membranes was formed.(1) Polyacrylate emulsion with first network structure was prepared by the way of micro-emulsion polymerization using n-butyl acrylatestyrene (n-BA), methyl methacrylate (MMA), iso-octyl acrylate (2-AEH), styrene (St) as comonomer, bifunctional monomer as crosslinking monomer. Sodium dodecyl sulfate (SDS), polyoxyethylene octylphenol ether (TX-30) as emulsifier, a-methacrylic acid (MAA) as the emulsifier and ammonium persulfate (APS) as initiator. The amount of emulsifier, the mass ratio of monomers, the amount of assistant emulsifier and reaction temperature impacted on the micro-emulsion particle size, Zeta potential, conversion rate and stability were studied by surface tension meter and Zetasizer Nano particle size analyzer. The results showed that when the mass ratio of SDS to TX-30was1:2(the amount was3.0-3.5wt%for the total latex system), the amount of MAA monomer was5wt%for the total monomer mass, the reaction temperature was75-80℃, the monomer conversion of microgel emulsion could reach96%, and the prepared polymer latex was stable.(2)Series of polyacrylate emulsion with the first network structure which changed proportion of cross-linking monomer in the comonomer were prepared. The effect of cross-linking monomer type and content in copolymer monomer on the appearance, mechanical properties, Tg and surface morphologies of the prepared polymer films were studied by using strength tester, DSC and scanning probe microscope. The results as below,(a) Adding more cross-linking monomer or nothing, the film-forming properties of the prepared films were poor. When the mass ratio of cross-linking monomer in the comonomer was about2wt%, the film-forming properties of the prepared films were the best.(b) When proportion of cross-linking monomer was the same in the comonomer, chosen cross-linking monomer A which has relatively long molecular chains. In the stress-strain curve, before strain reached250%, it could maintain the less stress and not changed. However, when chosen cross-linking monomer B with relatively short molecular chains. Stress raised in the uniform linear with strain. According to the experimental design, the cross-linking monomer A was chosen in the experiments(c) As the content of cross-linking monomer A increased form1to5wt%in the co-monomers, the Tg of the prepared polymer membrane was also increased, however, when the content of cross-linking monomer A was added above5wt%, the Tg of the polymer film was not increased.(d) The observation of the polymer film surface morphology and roughness with scanning molecules probe indicated that, as the content of cross-linking monomer in the comonomer increased, the roughness of the polymer membrane also increased.(3)The interpenetrating polymer network membranes were prepared by polyacrylate emulsion with the first network structure as component Ⅰ (AⅠ) and polyvinyl alcohol-glyoxal system as component Ⅱ (AⅡ). The effects of the content of cross-linking monomer in AⅠ, the ratio of AⅠ to AⅡ, curing temperature of membranes, etceteras on the mechanical properties, water absorption, dissolution-loss rate and Tg of the IPNs film were studied and characterized by infrared spectrometer, strength tester and DSC. The results showed that:(a) Adding appropriate cross-linking monomer into A I made the stress of the film remaining basically unchanged before strain250%and the stress increasing dramatically after250%, the results shows that the first network membrane was flexible, but strength was not enough. In addition, the small density and large grid of first network membrane could be conducive to the second network interpenetrating.(b) After interpenetrating polymer network membrane being formed, stress evenly increased with strain before the strain reached250%, the stress rapidly increased after strain reached250%, but was smaller than changes of the first network film after the strain250%, which showed that interpenetrating polymer network membranes maintained softness of the first network membrane, and also increased the "toughness" of the membrane.(c) After interpenetrating polymer network membrane being formed, the water absorption and dissolution-loss rate reduced, but Tg increased.(d) When the cross-linking monomer content was2%in AI, the ratio of m (PVA) and m (Glyoxal) was from1:0.2to1:0.4, the ratio of m (AⅡ) and m (AⅠ) was from1%to3%in A I, IPNs polymer film achieved the highest overall performance.(4)The paint dyeing coating was prepared according to coat-dyeing formulations with pigment printing binder AⅠand AⅡ. The effects of cross-linking monomer content in component AI, the mass ratio of polyvinyl alcohol and glyoxal in component AⅡ, the proportion of component AI and component AⅡ as well as the curing temperature on the dyeing properties of cotton fabrics were studied. The results show that:when the cross-linking monomer content in the component AI was2-3wt%, m(PVA)/m(Glyoxal) was1:0.2, m (AⅡ)/m(AⅠ)was2:100, the weight percent of total amount of component AⅠand AⅡ was15%for total amount of printing paste, as well as curing temperature and time was120℃and3min, The coating dyeing fabric could reach the optimum performance.(5) Polyacrylate reactive microgel was prepared by a emulsion polymerization method using styrene, a-n-butyl acrylate and methyl methacrylate as monomer, polyoxyethylene octylphenol ether (TX-30) and sodium dodecyl sulfate(SDS) as emulsifier, divinyl benzene and ammonium persulfate (APS) as cross-linking monomer and initiator, respectively. Microgels were put into coating dyeing adhesive. The effects of microgels on the rheological properties, leveling, mechanical properties and pigment printing performance of the prepared adhesives were studied. The microgel structure, particle morphology of microgel emusion and rheology of pigment printing binder were characterized respectively by infrared spectroscopy, TEM and rheometer. The color fastness of pigment printing and mechanical properties of adhesive film were characterized by friction color fastness test instruments and strength tester. The results showed that: the thixotropy, leveling and mechanical properties of adhesive printing binder as well as quality of pigment printing were improved when the microgel was added.