Towards understanding polyethylene terephthalete hydrolysis and aminolysis in tire cords

Abstract

Polyethylene Terephthalate (PET) is the most common thermoplastic in the industry. It is synthesized via polycondensation reaction between ethylene glycol (EG) and terephthalic acid (TPA) or dimethyl terephthalate (DMT). PET has variety of application areas and it is widely used in tire industry due to its high physical strength and chemical resistance. However, it is subjected to di erent types of degradations during synthesis and processing. PET tire cords su er especially from hydrolytic degradation during vulcanization where green tire is turned into standard tire with sulfur crosslinking with the help of accelerators. The degradation of PET is catalyzed by the released tertiary amines from the accelerators as a result of thermal decomposition. Quaternization was chosen as a method to address the problem which should block the tertiary amines' catalytic activities. TMP was chosen as an agent of methylation/quaternization. TMP was investigated for its methylation ability and chemical properties. Results show that both alkyl and aromatic amines can be quaternized/methylated by TMP. Then the study was focused to poly-2-vinyl pyridine containing latex (VP-latex), a coating used as an adhesion promotor in PET tire cords, which contain pyridine moiety that can potentially react with the TMP as a side reaction. First methylation of 2-vinyl pyridine units in VP-latex was investigated, then, its involvement in hydrolytic degradation was investigated via degradation studies.The results showed that VP-latex was not catalyzing the hydrolytic degradation of PET and it was inert to TMP.