Preparation And Characterization Of Polyacrylate Sizing Agent Modified By Nano-Montmorillonite

Sizing is an important section in textile industry, it's directly decide the quality and efficiency of weaving. At present, the widely used three main sizing agents have more or less different problems, in the practice of sizing agent modification, nano-materials brought new dawn for the improvement of sizing agents' properties.Montmorillonite (MMT) is one of the most widely used nano-materials, polymer molecular chains are directly combined with the montmorillonite silicate layers internal and external surfaces in the form of physical adsorption, at the same time, MMT silicate layers and polymer chains through intercalated molecules could be "compatibility" with MMT silicate layers, indirectly combined with the MMT silicate layers. As the combinations of these two areas are nanometer scale, the collective effect is intensified. Layered silicate is equivalent to the "physical cross-linking points" in polymer matrix, the physical cross-linking points and polymer chains boned together like the "nail anchor". In the composite materials, when the dispersion of the MMT silicate layers is better, or the interlayer spacing is lager, the probability of polymer molecular chains and silicate layer combinations is greater, the physical cross-linking points will be more, the enhance and toughen effects will be better.Polyacrylate sizing agents have the merits of adhesion and flexibility, etc., but the hygroscope, tackiness and the film is not tough enough are the disadvantages of this kind of sizing agent. The current study focused on polyacrylate sizing agents are use molecular design method, through analyze the function of monomer, target performance and molecular structure to synthesize new modified polyacrylate sizing agents, in order to develop new polyacrylate sizing agent which has moderate viscosity, good film performance. There could also use nano-materials, to improve the performance of sizing agent. In this paper, macromolecule design method and nano-materials were used together to synthesize a new type of polymer layered silicate nanocomposites sizing agent.In this paper, Cetyl Trimethyl Ammonium Bromide (CTAB) agent was used to modify the MMT firstly, the reaction conditions are at 60℃, 2.0CEC reagent dosage, 4 hours reaction time, the exchange of intercalation agent and cations which at the montmorillonite silicate layer makes the MMT internal and external surface from hydrophilic into hydrophobic, while the interlayer spacing increased, inter-layer micro-environment improved, surface energy became lowed, this all will help monomer or polymer intercalate into MMT layers to form nano-composites. Dispersion experiment indicated that after modification, the MMT became hydrophobic from hydrophilic, the effect is obvious.In this study, a series of polyacrylate sizing agents with different contents of MMT were prepared, infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) were used to characterize the molecular structure of nano-composites sizing agents and intercalated layer morphology; Glass transition temperature (Tg) of the nano sizing agents determined by DSC, the results show that when MMT content at low lever, could form an exfoliated structure. With the content of MMT increased, the Tg of the sizes raised.In addition, water-soluble and solution property of the sizing agents were tested, the results show that the appropriate amount of montmorillonite nano-materials added into the sizing agent can reduce the moisture absorption; reduce the viscosity and increase the liquidity; the modification sizing agents have good viscosity stability and miscibility.Adhesion test reveals that the nano-montmorillonite modified polyacrylate sizing agents have different adhesion mechanism to C and T/C, at last, yarn sizing test were used to comprehensive evaluate the performance of polyacrylate sizing agents. Compared with common polyacrylate sizing agents, this MMT nano-composite sizing agent can improve the abrasion resistance, enhance the strength of yarn and maintain yarn elongation. With the developing of nanotechnology and nano theory, more and more nanotechnology will be applied in the sizing agent, more and more high performance sizing agents will also be produced, to solve sizing problems, energy and environmental issues in textile.