Investigation In Preparation And Properties Of Waste Corrugated Paperboard Fiber/Starch Foam Composites

Starch-based foam composite is degradable by being prepared withstarch as matrix, modified with additives as plasticizer, compatilizer,foamer and processed by extrusion, injection or baking foaming. On theone hand, the starch-based foam composite has good biodegradation toreplace non-biodegradable foamed plastic especially EPS, so it makes forrelieving the problems of white pollution and oil shortage; On the otherhand, it is helpful to improve the added value of starch and addagricultural economic benefits; However, there are some commonproblems of the starch-based foam composite, such as poor compatibilityand water resistance, cells with uniform distribution and low expansionrate and rebound rate. Therefore, performance of starch-based foamcomposite is still not as good as EPS and limits its wide application in themarket. If we can get breakthrough the above problems, it will bring hopefor its application in the market.In the paper, waste corrugated paperboard fiber/starch foamcomposites（FFRSP） were prepared with starch and PVA as matrix,strengthened by waste corrugated paperboard fiber, modified withadditives as plasticizer, compatilizer, foamer and processed by injectionfoaming. Firstly, starch was plasticized by glycerol/urea to explore theplasticizing mechanism; Waste corrugated paperboard fiber was used toprepare fiber/starch composite and study its enhancement mechanism andEAA was used to research interface mechanism of fiber/starch composite;The influence of glycerol/urea、fiber、EAA content and temperature onthe melt rheology was reshearched. Secondly, it was investigated thatglycerol/urea、fiber、foamer、EAA content and injection molding processparameters (injection temperature, injection pressure injection frequency)effected in composites’ apparent density, expansion rate, rebound rate,degradability, melt rheology and cell expansion.The results showed that:(1) When mass ratio of glycerol and ureawas1to2, and their mass content was30%of starch, starch wasplasticized best, and its tensile strength increased by1.5times; When themass fraction of Waste corrugated fiber with being pretreated by concentration of4%sodium hydroxide solution was30%, fiber/starchcomposite’ tensile strength reached the maximum was11.4MPa; WhenEAA cotent was12%, it could improve interface compatibility of eachcomponent best, and its tensile strength increased to the maximum15.4MPa.(2) Melt shear viscosity was reducing with the increase of shearrate which was called as "shear thinned behavior"; When shear rate wasthe same, with increase of mixed plasticizer and foamer content, theshear viscosity were decreasing. However, with increase of fiber, shearviscosity was increasing; Shear viscosity was decreasing firstly with therise of temperature, then increasing; Shear viscosity was inecreasingfirstly with the rise of EAA content, then decreasing.(3) Rebound ratewas rising increasing of mixed plasticizer, fiber and foamer content, thenreducing; Apparent density was decreasing with increase of mixedplasticizer, fiber, foamer content and injection process parameters, thenincreasing; Expansion rate was raised with increase of mixed plasticizer,fiber, foamer content and the injection process parameters, then reducing;(4) The weight loss rate was increasing with time whose mixedplasticizer content was30%, fiber content20%, its degradation rate wasthe most appropriate among all.（5）Water absorption increased withincreasing foamer content, then decreasing; Water absorption of FFRSPwith3%content of water, FFRSP with2%content of NH4HCO3andFFRSP with3%content of AC/ZnO was respectively69.3%、62.5%、71.8%;(6) The cell size was more moderate with uniformer distribution,and its numbers were more, when foamed composite was produced with30%mixed plasticizer,20%fiber,3%foamer, and its injectiontemperature, pressure, rate was respectively140℃,70MPa and11g/s.