Accepted 11^th January, 2021

E.M.Abdelbary¹ and Ahmed Galal Seileem^2*
 

¹Faculty of Science, Mansoura University, Mansoura, Egypt.
²Materials Engineering Department, Faculty of Engineering and Materials Science, German University in Cairo(GUC), Cairo Egypt.

The reduction in molecular weight and viscosity of PET as recycled material impairs its mechanical properties. The difficulty of its processing using injection molding technique restricts its re-use as water bottle. Bottle to bottle recycling needs PET with relatively high molecular weight. Thus, the aim of this study is to restore the molecular weight and hence the viscosity of post-consumer PET bottles. The mechanical properties of PET in this study has been improved using blending techniques of virgin PET with different concentrations of waste PET with the addition of chemical extender such as 4,4’_Methylene-bis-(phenyl isocyanate) as additive. This led to an increase in the molecular weight and viscosity. Accordingly, the mechanical processing and the suitable processing parameters using injection molding technique were studied. The work is aimed at implementing a new scientific and production engineering technique which is fast and cost effective. Several testing methods such as DSC, FTIR, Rheometer and melt flow index have been used to characterize the samples. It has been found that it is possible to increase the molecular weight and viscosity index of recycled PET bottle to nearly the same level as that of virgin PET. Also, that it is possible to obtain competitive quality of PET waste material comparable to virgin PET in a single process using injection molding.

Key words: Poly(ethyleneterephthalate), recycling, injection molding, D.S.C., rheology.