| In recent years, with the increased awareness of environmental protection, peoplefocus on researches of natural fiber reinforced polymer matrix composites. In thisthesis, corn fiber, sisal fiber, corn and sisal hybrid fiber reinforced poly(lactic acid)(PLA) composites were prepared using injection molding. The static mechanicalproperties, dynamic mechanical properties, thermal properties and degradationproperties were studied. The influence of hybrid ratio and interface on hybrid effectwas discussed.Corn fiber was treated by alkali alone and the combination of alkali and silane. Inorder to study the influence of fiber treatment on static mechanical properties andthermal properties of composites, composites of corn fiber and PLA with differentfiber treatment were prepared. The results showed that both of alkali alone and thecombination of alkali and silane treatment can improve the interface bondingperformance of corn fiber and PLA, composites can obtain optimum comprehensivemechanical properties and thermal properties with corn fiber treated by combinationof alkali and silane.Composites of alkali treated corn fiber and alkali treated sisal fiber hybridreinforced PLA(AC/AS/PLA), untreated corn fiber and alkali treated sisal fiber hybridreinforced PLA(UC/AS/PLA), alkali treated corn fiber and untreated sisalfiber(AC/US/PLA) were prepared The results showed that AC/AS/PLA can obtainoptimum comprehensive mechanical properties when the hybrid ratio of corn fiberand sisal fiber was3:7. AC/AS/PLA and UC/AS/PLA has positive hybrid effect andAC/US/PLA has negative hybrid effect in the tensile, flexural and impact strength.Finally, the degradation property of PLA and the composites was studied Theresults showed that both PLA and composites have low degradation rate. Thedegradation rate of composites was significantly higher than PLA in alkali solution,acid solution and water. The degradation rate of composites was the highest in alkalisolution and the lowest in water. |
PDF Full Text Request