ABSTRACT
The development of a thermoplastic, biodegradable composite material to replace conventional polymers derived from petroleum was the main area of concentration. Herein, a method for preparing antibacterial, UV-blocking and degradable CNF/Lignin/PBAT composite films (CLP) using cellulose nanofibrils (CNF), lignin, and Poly (butylene adipate-terephthalate) (PBAT) as raw materials by solution casting method was described. With the adding of PBAT, the thermal stability, thermoplastic, mechanical properties were enhanced by improving the compatibility between components. The maximum tensile strength of CLP could reach 189.72 MPa, which increased 25.5 % compared to CNF/Lignin film. The average initial decomposition temperature could reach 321 °C, which was much higher than that of CNF and lignin. At the same time, its good heat-sealing performance made it suitable for practical use. Meanwhile, the composite films had excellent UV resistance and could block over 95 % of UV light. The antibacterial results indicated that the films had a good inhibitory effect on E. coli and S. aureus, with a maximum inhibitory ring diameter of 5.56 and 6.36 mm. In addition, the composite film also had excellent barrier capability to liquid and gas. The prepared film had potential to produce flexible packing, industrial compositing and biomedical fields.
Subject(s)
Anti-Bacterial Agents , Biomass , Cellulose , Escherichia coli , Lignin , Polyesters , Staphylococcus aureus , Ultraviolet Rays , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Lignin/chemistry , Escherichia coli/drug effects , Cellulose/chemistry , Polyesters/chemistry , Staphylococcus aureus/drug effects , Tensile Strength , Nanofibers/chemistry , Temperature , Microbial Sensitivity TestsABSTRACT
Defoliants carried by cotton fiber could harm production workers and consumers through respiratory and dermal exposure. This study was carried out to evaluate the dissipation behavior of four commonly used defoliants tribufos, diuron, thidiazuron, and ethephon in cotton fiber during field stage and also in cotton scouring using liquid chromatography and gas chromatography. Field trials showed that although all the defoliants dissipated fast, however, the fiber from the tribufos and ethephon applied field had considerable potential to exceed the maximum residue limit when the fiber was harvested at common intervals after application of defoliants. The defoliant residues could be removed completely from the defoliant-carrying cotton textiles during alkaline scouring. The results indicated that attention should be paid to the risk of occupational exposure to these defoliants rather than consumer exposure. Fiber harvest on the tribufos and ethephon applied fields is recommended after a 1-week delay in order to reduce the residues to an acceptable level.
ABSTRACT
Pesticides carried by cotton fiber are potential risk for production workers and consumers. Dissipation behaviour of a commonly used cotton pesticide profenofos in cotton fiber during growing period and scouring treatment was investigated. The results showed that profenofos in the fiber from the pre-opened and post-opened bolls both decreased to undetectable amounts 21 days after pesticide application. However, a minority of profenofos was converted to a strongly irritant compound, 4-bromo-2-chlorophenol and retained a non-negligible amount in cotton fiber even after 28 days. Profenofos and its degradation product could be completely removed during the conventional cotton scouring process. The degradation half-time of profenofos in scouring bath was only 3.0 min, and the degradation product was also 4-bromo-2-chlorophenol. Cotton products made of profenofos-carrying fiber are safe; however, the scouring waste should be detoxicated before discharge due to the accumulation of 4-bromo-2-chlorophenol in the scouring bath. These results could be useful for evaluating the risk of cotton fiber from the profenofos applied fields.