Study On GWT Transparent Agent And Its Application

As one of the paper chemicals applied in paper making process, the transparent agent can not only improve the transparency of the paper, but also meet other requirements as well. By replacing the plastic film with the degradable transparent or translucent paper mulch which was prepared by a transparent agent, the "white pollution" problem can be solved, and at the same time the production cost will be reduced. Therefore, the development of a high-efficient and low-cost transparent agent has both a theoretical and practical meaning for the industry. In this dissertation, the GWT transparent agent was prepared with emulsion polymerization method, and the performance and application of the transparent agent were studied in detail.The resulted GWT transparent agent is a kind of light yellow emulsion with solids content 40%, refractive index 1.51 and viscosity 18.8mPa.s. The GWT transparent agent could keep stable for a long time at room temperature without delamination or turbidity. The storage time and temperature had little influence on the transparent property of the agent, while it should be kept sealed because of its volatility.The transparency of the paper treated with GWT increased by 32.95% from 38.66%(base paper) to 71.61%. Keeping other conditions unchanged, the proper increase of the solid content of the transparent agent can lead to an improvement of the paper transparency, the optimal solid content is 30%.The dipping temperature and time can influence the performance of the transparent agent. Extension of the dipping temperature and time is beneficial for paper transparency. In short, the transparent agent can permeated rapidly at room temperature, the optimal time is 5 seconds. The scanning electron microscopy (SEM) images showed that the transparent agent has a good retention rate in base paper by adhereing to the fiber surface and filling in the interspace of the fibers.The GWT transparent agent has significant negative impacts on the paper’s tensile strength, bursting strength and the degree of permeability, also has a little adverse effect on tearing strength and the whiteness.The paper dipped with transparent agent has a good biodegradability. Buried in the soil after eight weeks, the mass loss was nearly 50.9%, also with a 90.2% loss in strength. After ten weeks, the mass loss was more than 55%. At last, the transparent paper disappeared totally in the soil after four months.The GWT transparent agent can improve little on the transparency of the unbleached base paper. It has little influence on the tearing strength and bursting strength, but considerable effect on the tensile strength. Therefore, the improvement of transparency should be focused on in our future work when unbleached paper is used as paper mulch.In brief, the production cost and intensity properites of the paper are still the main factors which limited its large-scale popularization and application.