| The development of science and technology has accelerated in recent years, all industries almost require high performances of trademark adhesive as focus.PVA(polyvinyl alcohol) trademark adhesive has the advantages, such as low cost, non-toxic, so it is a good development prospect of beer trademark glue; Beer market being increasingly competitive, the packing quality of labeling adhesive used for beer bottles is not only related to the appearance quality of beer, but also to factors such as labeling quality and production efficiency. However, the disadvantages of PVA trademark adhesive are poor water resistance and low temperature gel easily, so its market promotion and application are limited by greatly. So the study of PVA with a beer bottle labeling and the influence factors of PVA label glue water resistance, etc., has a certain practical significance.Having read on the basis of a large number of domestic and foreign literature, adopting the environmental protection free from contamination with strong hydrophilic hydroxyl of macromolecular polymer polyvinyl alcohol as the basic makings, through coordination ability with inorganic metal ions, the metal ions into PVA molecular chains, this paper prepares modified PVA glue with aluminum ion, modified PVA glue with Al3+/Zn2+ composite and modified PVA glue with Sn4+/Al3+/Zn2+ composite. Using the single factor experiment method and system research, this paper discussed the various factors on the preparation of modified PVA glue water resistance, and found the best preparation conditions of high water resistance of PVA glue. By using Fourier transform infrared spectrometer(FT-IR), scanning electron microscope(SEM), X-ray diffraction(XRD), thermogravimetric analyzer(TG) and contact Angle measurement instrument, products under the optimum process conditions prepared were characterized,such as the chemical structure, micro morphology, crystalline structure and thermal properties. Various kinds of the water resistance of preparation products were explored and studied. The main research work of this paper is stated as follows:(1) Study on modification and its water resistance of PVA trademark adhesive: with aluminium sulfate as inorganic crosslinking agent of PVA trademark adhesive, PVA molecules as the main chain of the modification, and the aluminum ions into the PVA molecular chain, using starch moderate thickening dispersion was prepared by an excellent water resistance PVA trademark adhesive. By means of single factor test method, the system research discussed the various factors on the influence of modified PVA glue water resistant performance, and explored optimum process conditions of preparation modified PVA trademark adhesive: PVA adhesive mass concentration was 20%, reaction temperature was 85℃, reaction time was 3h, aluminum sulfate was 4g, and starch was 8g.The best technological conditions prepared modified PVA trademark glue are as follows: contact Angle was 86.32°, water resistant time was up to 50 h, and water resistance was improved more than pure PVA glue.(2) Study on preparation and properties of PVA trademark adhesive with water resistance: using zinc sulfate and aluminium sulfate as compound modifier of PVA trademark adhesive, and using the single factor experimental method to explore the optimum process conditions of preparation modified PVA trademark adhesive. Discuss the effects of different factors on the viscosity and water resistance of before and after modification PVA trademark adhesive. Infrared spectrum analysis showed that PVA molecules successfully introduced aluminum ions and zinc ions, and that the number of hydroxyl groups were greatly reduced. The microstructure analysis by scanning electron microscope indicated that modified PVA film surface was rough, which showed that modified PVA trademark adhesive formed the network structure. X-ray diffraction(XRD) analysis results showed that PVA molecular hydrogen bonding was abated, and that the crystallinity was decreased. In optimum process conditions, preparation of PVA trademark adhesive of high water resistance showed that the viscosity(80Pa·s) was improved significantly: contact Angle increased from 50.39° to 105.46°, water resistant up to 72 h.(3) Study on influences of Sn4+/Al3+/Zn2+ on water-resistant properties of PVA trademark adhesive: using stannic chloride, zinc sulfate, and aluminium sulfate as compound modifiers of PVA trademark adhesive, the product by infrared spectrum analysis showed that the combination of Sn4+ and hydroxyl was easier than that of Al3+ and Zn2+, and water resistance was better. Microstructure analysis by SEM showed that Sn4+ modified surface roughness was more rough than that of Al3+, Zn2+. Thermal stability of the metal ions had almost no effect on PVA trademark adhesive; Contact Angle of modified PVA trademark adhesive was significantly larger, contact Angle of Sn4+ modified trademark glue was as high as 106.64°, and its water-resistant effect had improved significantly. Comprehensive performance of Sn4+ modified PVA trademark adhesive was relatively better than that of Al3+/Zn2+. |
PDF Full Text Request