Effect of surface treatments on the performance charecterıstıcs of natural fıber reınforced composıte materıals

ABSTRACT EFFECT OF SURFACE TREATMENTS ON THE PERFORMANCE CHARECTERISTICS OF NATURAL FIBER REINFORCED COMPOSITE MATERIALS KURT, Adem MSc. in Textile Eng. Supervisor: Prof.Dr. Aslı DEMİR October 2019, 70 pages With the legal regulations introduced within the scope of sustainability, recyclable composites produced from environmentally friendly materials have come to the fore in recent years. In this context, natural fiber reinforced composite materials gained popularity with their advantages such as light weight, recycling and lower cost. Flax fibers, which have superior mechanical properties than the other bast fibers, attract great attention as alternative reinforcement material. In the production of flax fiber reinforced thermoplastic composite material, polypropylene is the most suitable matrix as a matrix due to its limited temperature resistance. The most important problem between flax fiber and PP matrix is the lower adhesion due to the incompatible surfaces thus lowers the performance of composite material. In this thesis, composite surfaces were produced by using flax / polypropylene nonwoven surfaces in a blend proportions of 30/70 and 50/50. In order to overcome incompatibility of fiber-matrix interface surfaces, alkali treatment was applied as conventional modification method and ecological plasma and zein protein were applied as alternative methods. Untreated and surface modified samples were compared in terms of mechanical properties and their surface morphologies. The results indicated that plasma treatment was the most effective method for providing the adhesion of fiber-matrix interface surfaces. Key Words: Flax/polypropylene composites, surface modification, atmospheric plasma, alkaline treatment, zein