Research On Preparation And Performance Of Bagasse Fiber/Polyvinyl Alcohol Foam Composite

As the worldwide concentration of the environmental problems and the integration of global trade,the non-degradable cushion packaging materials will be ultimately weeded out.In order to replace the traditional non-degradable materials,the plant fiber foaming materials have become a research hotspot in our country and others.Although now the mechanical performance of some materials which has developed has almost be the same as traditional foamed plastic,its density was much higher than traditional foamed plastic.In this thesis,we take the bagasse fiber and polyvinyl alcohol as the main raw materials and adopt mechanical foaming method to make a new type of biodegradable packaging materials.On the basis of preliminary experiment,through the orthogonal experiment,we study the influence of various factors on porosity,density,stress and strain level,residual strain of the bagasse fiber and polyvinyl alcohol foam composite,and an optimized method was determined by the comprehensive evaluation.We study the influence of the main influence factors on mechanical properties and static cushion properties of bagasse fiber and polyvinyl alcohol foam composite through single factor experiments.We also study the changing rules of the mechanical properties and static cushion properties under different conditions of humidity and temperature.Orthogonal experiment results show that the content of PVA has the greatest effect on bagasse fiber and polyvinyl alcohol foam composite and the sodium tetraborate follows,the content of calcium carbonate has a minimal impact.The density of the foam composite is 0.0274 g/cm3 to 0.0811 g/cm3,belongs to high foaming materials,foaming ratio is 15~30 times.When it comes to comprehensive performance,the density of the optimum formula is 0.0614 g/cm3,consisted of bagasse fibers,polyvinyl alcohol,water,sodium tetraborate and calcium carbonate,the mass ratio is 10:16: 120:0.12:1.The bagasse fiber and polyvinyl alcohol foam composites get a perforated structure,the mechanical properties of the material strengthen with the increase of PVA content;Trace content of the sodium tetraborate can produce a significant change on foam ratio of the materials,the mechanical properties of the material strengthen with the increase of sodium tetraborate content;with the increase of the content of water,the mechanical properties of the materials decrease after increasing first.The mechanical properties and static cushion properties of the foam composite have almost be the same as EPS.In the low level of density,the mechanical properties of the bagasse fiber and polyvinyl alcohol foam composite can be greatly affected by temperature and humidity;in the high level of density,the mechanical properties of the foam composite change little;the minimum buffer coefficient of the material reduce when the humidity decrease or the temperature increase.