بررسي خواص مكانيكي پلي پروپيلن پرشده با الياف زيست تخريب پذير كنف

چكيده انگليسي :

002 Study of the Mechanical Properties of Polypropylene Filled with Biodegradable Kenaf Fibers Mohammad Nematollahi mohammad nematollahi@me iut ac ir Date of Submission 2016 06 29 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors Mahmoud Farzin farzin @ cc iut ac ir Peiman Mosaddegh mosadegh@ cc iut ac irAbstract In recent years the application of natural fibers as a substitute for man made fibers in compositeswith polymer matrix has been widely increased Natural fibers have some advantages such as low density low cost high specific strength and biodegradability In contrast the main problem associated with thesefibers as reinforcing of composites is their weak compatibility with the matrix especially in the field ofnon polar polymers Using conventional thermoplastic polymers and especially polyolefins play animportant role in making thermoplastic compounds In this study a polypropylene which is a useful andinexpensive thermoplastic has been used as a matrix and natural kenaf fibers that are found in abundancein the country has been applied as the reinforcement Melt mixing and injection molding are conventional useful and fast methods in makingthermoplastic composites Therefore in this study reinforced polypropylene composites with 10 20 30 and 40 of kenaf fibers were made by this method since one of the advantages of this method isappropriate dispersion of fibers in the polymer matrix To overcome the problem of weak compatibility ofthe fibers and matrix and to improve the interface between the polar fibers and non polar polymer matrix inaddition to the fiber surface modification the Maleic Anhydride Polypropylene MAPP coupling agentwas employed The objective of this study is to evaluate the mechanical properties of polypropylene filled withkenaf fibers and also to find a relationship between the mechanical properties and some of the structuralfactors related to composites The tensile bending and impact tests were conducted to evaluate themechanical properties and also the cross section of fracture of composites was observed and analyzed bythe SEM DSC thermal analysis results showed the percent crystallinity of samples and also the effect offibers and its amount on the melting behavior and crystalline polypropylene In addition XRD analysis toidentify the type and size of the crystal is also performed on the samples taken and FTIR testing to find theoptimal amount of time and percent NaOH is used to surface treatment of the fibers The results of Mechanical test show that by increasing the percentage of fibers to thepolypropylene matrix the stiffness modulus and strength is improved significantly while the toughness impact strength had a small decrease Also FTIR results showed that the treatment process has improvedthe interaction between the fibers and the polypropylene matrix this adaptation has been more developedby the presence of MAPP The SEM images confirmed these results as well The DSC and XRD tests alsoshow that by increasing the percentage of fibers the crystallinity of composites was developed Keywords Biodegradable Natural fiber Polypropylene Composite Mechanical properties Injection molding

نعمت اللهي، محمد

بررسي خواص مكانيكي پلي پروپيلن پرشده با الياف زيست تخريب پذير كنف

كامپوزيت , اختلاط مذاب