| Textile functional finishing is able to give a specific function to fabrics, so it meets the direction of market diversification and the various demands of consumers, but it usually has serious problems such as energy consumption and pollution discharge. This study applied the mechanism of photocuring reaction and referred the spray method of digital inkjet printing. A new concept of blue light curing for textile digital functional finishing was proposed, namely photocuring oligomers, monomers, photoinitiator and functional substances were firstly sprayed on demand to the surface of the fabrics, and then free radical polymerization was induced by blue light to form macromolecules film instead of the padding and drying steps in traditional thermal curing. The photopolymerization system composed of oligomers and monomers determines the basic properties of the cured film. Accordingly our study designed a systematic research of photopolymerization system to develop an exclusive flexible blue light curing polymerization system for textile digital functional finishing. The study will lay the theoretical foundation of the intergrated innovative application combined blue light curing technology with digital processing technology in the field of textile dyeing and finishing.Firstly, we studied the kinetics and mechanism of free radical polymerization induced by blue light; Real-time FTIR-ATR and differential scanning photo-calorimetry were adopted to give a tracking analysis about the influence of blue light intensity, the mass ratio of camphorquinone (CQ) and ethyl4-dimethylaminobenzoate (EDB), the concentration of CQ photoinitiator on the photopolymerization kinetics of typical monomer, tripropyleneglycol diacrylate (TPGDA); moreever, the initiate mechanism of CQ/EDB initiation system was discussed. The results showed:CQ transforms into excited state by absorbing the energy of blue light and has the hydrogen-donating reaction with EDB to form tertiary amine free radical which induces the chain propagation reaction of TPGDA; to achieve high double bond conversion, the optimized initiator conditions were as follows:blue light intensity16.9mW/cm2, the mass ratio of CQ and EDB1:1, the concentration of CQ0.5wt%.Then, the relations between the chemical structure of acrylate monomers and the mechanical properties of blue light cured films were explored to provide theoretical guide for the development of blue light cured flexile polymerization system. The conclusions were listed below:on the premise of approximate chain length, the tensile strength and glass transition temperature (Tg) of films increased and the flexibility became worse as the monomer functionality increased; as the chain length increased, the tensile strength, flexibility and Tg of film decreased; When a-methyl substituent was added, the tensile strength and Tg of films increased and the flexibility decreased.Finally, systematic research was carried out in Aliphatic PUA system, Epoxy-PEA system and HBPUA system for the optimization of blue light cured nontoxic, tasteless, strong, flexile polymerization system and the standard establishment in textile digital functional finishing; the ultraviolet resistance digital finishing of cotton fabrics were promoted to learn the feasibility of polymerization system in practical application. Main research findings were as follows:blue light polymerization system in textile digital functional finishing①80/20Aliphatic PUA/TPGDA,②60/40Aliphatic PUA/HEMA,③60/40Aliphatic PUA/IBOMA,④60/40Epoxy-PEA/TPGDA,⑤60/40Epoxy-PEA/IBOMA,⑥80/20HBPUA/TPGDA; Parameter standard:tensile strength2.5-10MPa, flexibility0.5level, Tg25-85℃, viscosity at room temperature55-750cPa·s; the ultraviolet transmittance of cotton fabrics after finishing was below3%and the UPF value was85-92, the strength of fabrics improved and the handle had little change, the difference between various polymerization systems was not so obvious. |
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