Study On Cellulose/P34HB Composite Packaging Film

In order to reduce the pollution of the traditional plastic packaging and improve the application of renewable materials,the development of environmentally friendly biodegradable packaging materials has been developed.In this paper,the regenerated cellulose film was used as the matrix,3-hydroxybutyrate-co-4-hydroxybutyrate)(P34HB)was used to prepare green biodegradable cellulose/P34HB composite packaging film.The structure and properties of the conposite packaging film were studied.The main results are as follows:(1)The films prepared by drying at room temperature was denser than that of freeze-drying.For the same drying method,the structure of ethanol was the most compact,and the sodium sulfate had the pore structure.For the same drying method,the crystalline of regenerated cellulose film prepared by sodium sulfate was the largest,and the smallest crystalline of regenerated cellulose film was prepared by sodium sulfate.The crystalline of the regenerated cellulose film produced by the freeze-drying method is larger than that of the regenerated cellulose film prepared by the room temperature drying method.The mechanical properties showed that the regenerated cellulose films produced by the room temperature drying method had a higher tensile strength than that obtained by the freeze drying method.For the same drying method,the greater the crystalline,the greater the tensile strength of the film.The regenerated cellulose films produced by the freeze-drying method are mainly mesoporous.(2)With the increase of P34HB content the convex structure of cellulose/P34HB composite packaging film gradually flattened,and the cross-sectional structure gradually became smooth During the crystallization process,the structure of cellulose gradually disappeared with the increase of P34HB,the porous structure of cellulose matrix increased the crystalline of P34HB and decreases the crystal size.Infrared spectroscopy and XRD analysis showed that there was no correlation between P34HB and cellulose,both of which showed a state of separation.(3)The tensile strength of the cellulose/P34HB composites increased first and then decreased with the increase of P34HB content.When the content of P34HB was 30%,the tensile strength of the composite film was the highest is 5.09MPa,which is 48%higher than that of the regenerated cellulose film.At this time,the elongation at break is the largest,the value is 6.82%,which is 25.1%higher than that of the regenerated cellulose film.With the increase of P34HB content,the hydrophobicity of cellulose/P34HB composite film gradually increased,the hydrophilicity gradually weakened,and the permeability coefficient of water vapor showed a decreasing trend.