Synthesis And Application Of Pigment Printing Binder With Interpenetrating Polymer Networks

Polyacrylate(PA) binder has been widely used in pigment printing industry because of its good adhesion, transparency, chemical resistance, and low cost, but some inherent disadvantages of polyacrylate binder are difficult to overcome, such as stiff hand feeling and poor fastness. Organosilicon has become a research hotspot of polyacrylate emulsion modifying agent because of its good flexibility, water resistance and stability, of which preparation of organosilicon-polyacrylate interpenetrating polymer networks(IPNs) is one of the most effective methods. Therefore, in this paper, an interpenetrating polymer networks emulsion was prepared from cross-linked polydimethysiloxane(PDMS) as the first polymer network matrix and self-crosslinked polyacrylate(PA) as the second network. In addition, the application in pigment printing was discussed.Firstly, cross-linked polydimethysiloxane emulsion was prepared with the method of cationic ring-opening polymerization using octamethylcyclotetrasiloxane(D4) as monomer, iso-tridecanol polyoxyethylene ether(1309), sodium dodecyl benzene sulfonate(SDBS), sodium dodecyl benzene sulfonate(SDS) as emulsifiers, and tetraethoxysilane(TEOS) as crosslinker. The optimal polymerization conditions for the PDMS emulsion were determined as 10.0wt% DBSA, 3.0wt% emulsifier, 1:2-1:3 composite ratio of emulsifier, reaction temperature 80-85℃, and preservation time 4.0h via analyse of polymerization stability, emulsion stability, conversion rate of D4, particle size and distribution of PDMS emulsion. As a result, the PDMS emulsion was prepared with particle size about 100 nm, narrow particle size distribution, good stability and the highest conversion rate of 85.9%. The crosslinking degree of netwok I PDMS was 9.11% by adding 3.0wt% TEOS and suitable for preparing IPNs.Secondly, modified acrylate interpenetrating polymer networks emulsion was prepared on the basis of polysiloxane network I matrix, with the method of both pre-emulfication and pre-swelling seeding emulsion polymerization, using butyl acrylate(BA), methyl methacrylate(MMA), styrene(St) as comonomers, composite emulsifier as in the network I, diacetone acrylamide(DAAM) and adipic dihydrazide(ADH) as self-crosslinker and potassium peroxodisulfate(KPS) as initiator. The optimal polymerization conditions for the IPNs emulsion were determined as 3.0-5.0wt% emulsifier, 0.30-0.50wt% KPS, 3:1-2:1 ratio of hard and soft monomers and 25.0wt% PDMS of total polymers. As a result, the IPNs emulsion was prepared with particle size about 100 nm, narrow particle size distribution, good stability and the highest conversion rate of 93.7%. IPNs emulsions showed narrower particle size distribution via pre-swelling seeding emulsion polymerization method. The mechanical property, microscopic morphology and latex properties of IPNs were discussed using FTIR, TEM, SEM and TGA, which showed obvious improve ment of interpenetration and compatibility of PDMS and PA network.Furthermore, IPNs binder emulsion were applied to pigment printing of weaven cotton. The optimal formulation for the pigment printing were determined as 25.0wt% binder, 1.50wt% thickener PTF and drying in low-temperature, using IPNs emulsion prepared with 3:1 ratio of hard and soft monomers, 4.0wt% self-crosslinker of network II, and 25.0wt% PDMS of total polymers. As a result, the printed fabric using binder prepared with pre-emulsification method showed stiffness 2.6 cm(3.2 cm of the original fabric), dry rubbing colour fastness 4-5 degree and wet rubbing colour fastness 3-4 degree; the printed fabric using binder prepared with pre-swelling method showed stiffness 2.2 cm, dry rubbing colour fastness 4 degree and wet rubbing colour fastness 4-5 degree in consequence of improvement of its compatibility. The printed woven fabrics showed soft hand feeling and good rubbing fastness in low-temperature drying without curing.