Preparation And Characterization Of Polylactic Acid (PLA) Based Slow/Controlled Release Membrane

In order to study the organic polymer membrane materials with slow/controlled release effect, this paper studied the effects of the biodegradable polylactic acid (PLA) as the membranes substrate, the animal/vegetable oil as the additive, dichloromethane as solvent, preparation of membrane fluid, through the salivation method to prepare the blending membranes.Firstly, the polylactic acid-animal/vegetable oil-dichloromethane blends were studied. Polylactic acid - animal / vegetable oil - dichloromethane ternary system phase diagram. The reason why the structure of the "island" was formed was that the solubility parameters of the polylactic acid and the animal oil were different, and the blends were difficult to form Homogeneous system, polylactic acid belongs to the polymer, can form a single continuous phase,animal/vegetable oil is a small molecule, the viscosity is small, can not form a single continuous,After the volatilization of methylene chloride / vegetable oil is nested in the polylactic acid phase, the two form an "island" structure.Secondly, the effects of the mass ratio of PLA to animal / vegetable oil on the surface structure, hydrophobicity, Tensile strength, water holding capacity and water content, dialysis coefficient and cumulative release of ammonium chloride were investigated by using a series of membraness prepared. The results show that:1. Compared with the blending membrane prepared by using the animal oil as the additive, the "island" structure of the "island" structure formed by the plastic membranes as the additive is smaller, the distribution is more uniform, the contact angle is small, the membrane The tensile strength and the cumulative release of ammonium chloride were higher. 2. With the increase of the ratio of animal /vegetable oil to PLA, the "island" structure of the blending membrane was " "The larger, the contact angle, the dialysis coefficient, the cumulative release of ammonium chloride increases, the tensile strength and moisture content of the blending membranes decreases.Finally, application of ultrasonic cavitation effect, ultrasonic treatment of membrane fluid, and then made of membranes. The effects of ultrasonic time and ultrasonic temperature on the properties of the blending membranes- were investigated. The results show that: 1. The effect of ultrasonic temperature on the membrane is smaller; 2. The longer the ultrasonic time, the "island" structure increases, the contact angle increases, the water content increases and the water holding capacity decreases And the cumulative release of ammonium chloride increased.