BİLDİRİ DETAY

Seda HAZER, Meral ÇOBAN, Ayse AYTAÇ
THE INVESTIGATION OF THERMAL PROPERTIES OF GLASS FIBER REINFORCED PLA/PC COMPOSITES
 
Abstract: Introduction: Usage of large-scale petroleum-based polymer create an important environmental problem such as solid waste management. Poly (lactic acid) (PLA) is the degradable polymer and it is obtaining by fermentation from renewable resources such as corn or sugar beet [1,2]. Compostable and biodegradable properties of PLA provide a useful solution to solid waste management problems. PLA is promising polymer among the biodegradable polymers due to its good mechanical properties such as high mechanical strength. Besides, the other properties of the PLA are gas permeability, good biocompatibility and high transparency. Benefit from the use of PLA in many applications such as in automotive components, electrical industry, building materials, and the aerospace industry. However, low toughness and easy flammability properties restrict usage of PLA for different industries. The toughness of PLA can be improved by adding plasticizer or blending with the other polymers. On the other hand, polycarbonate (PC) which has high thermal stability, toughness, easy processability and high tensile strength, has been widely used as an engineering plastic [2]. Enormous mechanical properties such as high toughness demonstrated of the PC's can be combined with PLA in the PLA/PC blends. However, the mechanical properties of the resulting blend are lower than expected value due to the incompatibility of these polymer [3,4,5]. Synthetic fiber reinforcement is a commonly used method to improve mechanical properties of the neat polymers. Goal: It was aimed to improve the decreasing mechanical properties and thermal properties of PLA/PC blend due to the incompatibility by reinforcing with synthetic fiber. The mechanical, thermal and morphological properties of glass fiber (GF) reinforced PLA/PC blends were examined with the increasing loading level of GF. Method: Primarily, a PLA/PC (50/50) blend was prepared and were used as the control sample. Loading levels of GF were changed as 5 wt.%, 10wt.%, 15wt.%, 30wt. %. All composites were compounded on a laboratory scale co-rotating twin-screw mini-extruder (Micro-compounder) with a screw speed of 100 rpm. Samples were subsequently injection molded by using a laboratory scale injection molding machine with a 10 bars injection pressure. Discussion: Characterization of the composites were performed by differential scanning calorimetry (DSC), tensile test, thermogravimetric analysis (TGA), limiting oxygen index (LOI) and scanning electron microscope (SEM). Results: The highest crystallization degree and Tg value were obtained PLA/PC (50/50) blend 23.3 % and 65°C, respectively. 5wt.% GF addition decreased the crystallization degree of the sample. Also, the crystallization degree of the prepared composites enhanced by increasing GF content. While the addition PC to the PLA increased LOI value of neat PLA, enhancing GF content decreased LOI values of the composites. Generally, the strain at break values of the composites was decreased with the increasing loading level of the GF. In addition, it is observed that the strain at break values of the 5wt.% GF composite was higher than neat PLA. The tensile strength and modulus value of the PLA/PC blend were improved by the addition of the GF. Furthermore, the maximum tensile strength value was obtained from the 30 wt.% GF reinforced PLA/PC blend as 110.18 MPa.

Anahtar Kelimeler: Biodegredable,Glass Fiber, Mechanical Properties



 


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