Preparation And Properties Of The Pesticide Microcapsule Paper-based Film

The materials PVC and PE are commonly used for insecticidal mulch film and are difficult to be degraded in soil. Moreover, the soil will be wrapped and agglomerated, and bad for the growth of crops. Generally, the preparation process of insecticidal film constantly lead to the uneven distribution and waste of pesticides. In some extent, the application is largely limited. Therefore, the process optimization of biodegradable film and suitable insecticides become extremely important. In this paper, we successfully fabricated the chlorpyrifos microcapsule and impregnated that onto the paper-based film of waste cotton fiber by adhesive, which can ensure the efficiency of chlorpyrifos and protect environment for the degradation of chlorpyrifos-PCL microcapsule and paper-based film.In order to prepare a high performance paper-based film, the wasted textile cotton fiber was choosen as the main raw material and some waste paper pulp as the secondly material. Results showed the optimal forming conditions of paper-based film were as followed. When the mass ratio of waste cotton fiber and waste paper was 95:5, the cationic starch was 1 wt%, the cationic polyacrylamide was 0.7 wt%, wet strength agent was 0.6 wt%, the water soluble PVA fiber was 10 wt%(relative to the absolutely dry pulp), the properties of the paper-based film were as followed: the tensile index was 42.7 N·m2/g, the tear index was 67.1 m N·m2/g, the wet strength index was 25.7 N·m2/g, the wet strength retention rate was 49.4%, the degradation rate could reach 40.3 % after 50 days.Chlorpyrifos-PCL microcapsule, which were composed of chlorpyrifos as core material, PCL as shell material, were prepared by the way of O/W emulsion solvent evaporation method. The microcapsule has the optimized performance under the following preparation condition, the PCL concentration in the organic phase was 3%, the concentration of PVA in the aqueous phase was 2%, the ratio of core to wall was 1:3, the emulsion speed was 6000 r/min, emulsion time was 15 mins. Results showed that the microcapsule size was homogeneous and the average particle size was approximately 6.05 μm. The release rate of chlorpyrifos reached 90% after 30 days.We used the styrene-butadiene latex as the binding stuff and impregnated chlorpyrifos-PCL microcapsule onto the paper-based film. Results showed that when the dosage of microcapsule, strene-butabiene latex and sodium polyacrylate was 6%, doasge was 2% and dosage was 0.3%, the tensile index of the pesticide microcapsule mulch film could reach 46.55 N·m/g, the tear index increased to 68.53 m N·m2/g, the burst index was 4.7 KPa·m2/g, the air permeance was 3.3 m L/min. The release rate of chlorpyrifos was 80 % after 28 days.