Assembly And Functionalization Of Different Polysiloxanes On The Fiber/Fabric Susbtrates

Polysiloxanes are low energy materials with good film-forming capacity. When coated and anchored on hydrophilic fiber/fabric surfaces, polysiloxanes not only modify the surface properties of the treated substrates greatly, but also could provide the treated fiber/fabrics with softness, smoothness, hydrophobicity as well as diversified tactile. These excellent properties make the polysiloxanes have been widely used as softeners, lubricants or waterproofing agents in textile industry.Functional polysiloxanes have presented in textiles for years, but how to design and synthesis new structure polysiloxanes or the polysiloxanes with outstanding performance such as super-hydrophobicity have still attracted the world attention recently. In addition, architecture of super-molecular polysiloxanes which will give special oily handles from counter-charged polysiloxanes such as amino- and carboxyl-containing polysiloxanes, as well as the preparation of super-hydrophobic textile with fluorinated siloxanes and their derivatives have also been active field in the polymeric material. To correspond with these, we have done the following work in the research:1. To prepare superhydrophobic cotton textile from N-β-aminoethyl-y-aminopropyl substituted polydimethylsiloxane (ASO-1)(1) Using N-β-aminoethyl-y-aminopropyl substituted poly dimethyl siloxane (ASO-1) as hydrophobic material and as solvent, a soft but hydrophobic cotton fabrics (ASO-1/Fab) with a water contact angle (CA) of 150.5°was prepared by dipping the fabric, with a rough surface on nano- meter scale, in ASO-1-toluene solution for several seconds, then dried and cured at 170℃. Surface composition and morphology of ASO-1/Fab were characterized and investigated by field emission scanning electron microscope (FESEM), attenuated total reflectance (ATR) infrared spectrum, X-ray photoelectron spectroscopy (XPS), and so on. And the influencing factors on ASO-1/fab superhydrophobic property were also investigated. It was discovered that the dosage of ASO-1, and the immersing time of fabric in ASO-1-toluene solution as well as the amount of cross-linking agent could influence the super-hydrophobicity of ASO-1/Fab. As a result, an optimum CA of ASO-1/Fab was obtained by co-operation of ASO-1 with y-aminopropyltrimethoxysilane.(2) Water contact angles of treated cotton fabrics could be improved by using ASO-1 and the roughed cotton substrates by SiO2 sols. The experiment results showed the CA, which were more than 160.5°, had been successfully obtained from the cotton fabrics treated by 0.25wt% ASO-1 solution and SiO2 sols with diameters of 30-280.7nm. When the diameter of SiO2 sol increased 280.7nm, the CA of the treated fabrics could reach to 165.2°.(3) In order to further improve the hydrophobicity of ASO-1 and enhance the fixation of nano-SiO2 on fabrics, two nano-SiO2 hybrid polysiloxanes, ASO-SiO2 (which was prepared from ASO-1 and y-(2,3-epoxypropoxy)propylsilane modified nano-SiO2) and PEMS-SiO2 (which was prepared from ASO-1 and y-aminopropyltrimethoxysilane modified nano-SiO2) were prepared and used to treat cotton fabrics in the experiment. Composition and hydrophobic properties of the two nano-hybrid polysiloxanes were investigated by IR, XPS and other instruments. Experiment results indicated that such hybrid polysiloxanes could impart the treated cotton fabrics with an improved hydrophobicity. The CAs of the treated fabrics were 155.0°for 0.25wt% ASO-SiO2 and 155.3°for 0.25wt% PEMS-SiO2, respectively.2 Novel N-β-aminoethyl-y-aminopropyl-substituted poly [methyl (3,3,3-trifluoropropyl)]-co-dimethylsiloxane copolymers AFMS and AFSO were prepared by bulk polymerization of 1,3,5-trimethyl-1,3,5-tri(3,3,3-trifluoropropyl) cyclotrisiloxane (D3F) with N-β-aminoethyl-y-aminopropylmethyldimethoxysilane and other monomers. Structure of AFMS and AFSO was characterized by IR and 1H-NMR and performance properties were studied. The results indicated contact angles of the fabrics treated with 0.25wt% AFSO and AFMS in toluene solution could reach to 151.2°and 152.0°, respectively. And moreover, CAs could enhanced to 161.3°nd 161.8°if the cotton fabric was pretreated with SiO2 sol (with a diameter of 313.9nm) or with a mixed silica sol (with diameters of 79.7nm and 313.9nm) before 0.25wt% AFMS solution treatment.3 Two kinds of reactive epoxy/fluorinated long alkyl modified polysiloxanes (PPT and PPD) and another two reactive polysiloxanes (PFSEAS and PFEAS) with epoxy/polyether/ fluorinated long alkyl groups were prepared by hydrosilylation of poly(hydrogen methylsiloxane-co-trifluoropropyl methylsiloxane) (PFHMS) with 1,1,2-trihydrogen vinyl perfluorodecene (PFOE) and allyl glycidyl ether (AGE) and other monomers. Structure and film morphology as well as hydrophobicity of the synthesized polysiloxanes on cotton fabrics were characterized and investigated by IR,1H-NMR, AFM and so on. Influenced by hydro-/lipo-phobic property as well as the spatial effect of the fluorinated long alkyl groups, and long fluorohydrocarbon groups were distributed on the film surface uprightly or slantingly, resulting in a jagged rough morphology on the treated substrate surface. When polyether groups were introduced in the side chain of fluorinated polysiloxanes, larger aggregates derived from polyether groups were observed on the polysiloxane film, leading to a rougher surface. However, polyether groups could decrease hydrophobicity of the polysiloxane film. As a result, CAs of the fabrics treated with PPT and PPD were 150.4°and 151.9°, while CAs of the fabrics treated with PFSEAS and PFEAS were only 129.2°and 134.3°, respectively.4 y-(N-carboxylacrylate) aminopropylmethylsiloxane-co-dimethyl-siloxane copolymer(carboxylpolysiloxane for short, CAS) was prepared by ring-opening action of cis-butenedioic anhydride and y-aminopropyl polysiloxane. AFM and other instruments were used to characterize and investigate its structure, film-forming ability and morphology.On this basis, with ethyl acetate used as solvent, ASO and CAS were assembled through antistatic interaction, then anchored on the fiber and silica substrates and ASO/CAS supermolecular film was obtained, film structure, morphology and performance of which were investigated by AFM, FE-SEM and other instruments. The results indicated that ASO/CAS, formed by blending equivalent amount of ASO and CAS in ethyl acetate solution, showed a highly ordered, window grating-like structure in micro-morphology, with a assembly-layer number of 2～3. When used for cotton fabric finishing, ASO/CAS could improve softness of the fabric obviously, with a unique oily handle exhibited. The optimum softness and unique oily handle can be obtained only when the mass ratio of ASO to CAS is 1:1.