Geri Kazanılmış PET/PEN Karışımlarının Özelliklerinin Farklı Zincir Uzatıcılar Kullanımı ile İyileştirilmesi

PET/PEN mixtures have been studied extensively in the literature for the production of materials with economically viable and superior properties. However, as it is known, PET and PEN are not compatible polymers with each other and various methods are used to harmonize these mixtures. One of these methods is the transesterification reaction of PET and PEN during mixing from the melt. However, during transesterification, the molecular weight of polymers decreases by exposure to thermal, hydrolytic and oxidative degradation. Adding chain-extending chemicals to the mix to reduce this effect is one of the methods used. In this study, the effect of 1, 4 phenylene bis, oxazoline (PBO), tri phenyl phosphate (TPP) and 1, 4 phenyl diisocyanate (PDI) chain extenders on the properties of PET/PEN mixtures prepared with recycled PET (r-PET) was investigated. First of all, the effect of PEN amount on r-PET-PEN mixtures was examined and 70/30% r-PET-PEN mixture was determined as control sample. Later, chain extenders of 0.5, 1.0 and 2.0 wt.% were added to this composition. Tensile and impact tests were performed to examine the effect of chain extenders on the mechanical properties of r-PET-PEN mixtures. Differential scanning calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to determine the glass transition temperature. The level of the transesterification reaction was calculated using the Nuclear Magnetic Resonance Spectroscopy (H1-NMR) technique. In the light of all these data, it was determined that PDI was the most suitable chain extender for r-PET-PEN mixtures, while TPP was not a suitable chain extender for this mixture.