Water Vapor Sorption Properties of Polyethylene Terephthalate over a Wide Range of Humidity and Temperature

Abstract

The dynamic and equilibrium water vapor sorption properties of amorphous polyethylene terephthalate were determined via gravimetric analysis over a wide range of temperatures (23-70 °C) and humidities (0-90% RH). At low temperature and relative humidity, the dynamics of the sorption process was Fickian. Increasing the temperature or relative humidity induced a distinct up-swing effect, which was associated with a plasticization/clustering phenomenon. For high temperatures and relative humidity, a densification of the polymer was evidenced. In addition to the classical Fickian diffusion, a new parameter was introduced to express the structural modifications of PET. Finally, two partial pressures were defined as thresholds that control the transition between these three phases. A simplified state diagram was finally proposed. In addition, the thermal dependence of these sorption modes was also determined and reported. The enthalpy of Henry's water sorption and the activation energy of diffusion were independent of vapor pressure and followed an Arrhenius law.

Impact of hydrolytic degradation on mechanical properties of PET - Towards an understanding of microplastics formation

“…Therefore, the time needed to reach saturation within the different specimens is very short compared to the ageing times considered in this study. To support this, in reference [26], results from water permeation data on PET can be found over a wide range of temperatures and humidity conditions. In particular, the authors state that at 70°C and humidity conditions between 10-30% relative humidity, the diffusion coefficient is 8.0.10 -…”

Biochemodynamic Features of Metal Ions Bound by Micro- and Nano-Plastics in Aquatic Media

“…a“Structural” denotes elements that were an inherent component of the polymer matrix; “non-structural” means that the elements were not an inherent component of the polymer matrix; “unplasticized” means no added plasticizing agents; “plasticized” means plasticizing additives are presentb Wang et al, 2011 ;c Doty et al, 1944 ;d Hauser and McLaren, 1948 ;e Métayer et al, 1999 ;f Marais et al, 2000 ;g Penon et al, 2007 ;h Tong-That and Jungnickel, 1999 ;i Yasuda and Stannett, 1962 ;j Yi and Pellegrino, 2002 ;k Doty, 1946 ;l Mountz et al, 2005 ;m Dubelley et al, 2017 ;n Langevin et al, 1994 ;o Burgess et al, 2014 ;p Rueda and Varkalis, 1995 ;q Schollmeyer et al, 1976 ;r Fukuda et al, 1990 ;s Sammon et al, 2000 ;t Kloppers et al, 1993 ;u Reuvers et al, 2014: measured Mn diffusion into polymer from aqueous solution of MnCl 2 ;v Broudin et al, 2015 ;w Hernandez and Gavara, 1994 ;x Monson et al, 2008 ;y Arhant et al, 2016 ;z Hnatowicz et al, 1994: measured Pb diffusion into polymer from aqueous solution of Pb(CH 3 COO) 2 ;aa Tocháček and Sidlár, 1990: metals are present as complexes with (i) 6-[3-(3,5-di-t-Bu-4-hydroxyphenyl)propanamido]caproic acid or (ii) 3-(3,5-di-t-Bu-4-hydroxyphenyl)propionic acid ;ab Chmiel et al, 2003: measured diffusion of Zn into polymer from aqueous solution of ZnCl 2 ;ac Mercea et al, 2018: Cd and Zn probably present as stearates, Pb present as (i) mixture of lead stearate and dibasic lead phosphite, (ii) unknown forms, (iii) lead stearate, (iv) dibasic lead phos...…”

“…The diffusing metal ions are proposed to be at least partially hydrated (Reuvers et al, 2014). The permeation of water into the polymer phase causes a degree of plasticization and a reduction in the glass transition temperature, which in turn can modify the diffusivity of water (Marais et al, 2000; Mountz et al, 2005; Reuvers et al, 2015; Dubelley et al, 2017). Nevertheless, across all polymer types shown in Table 1, the effective diffusion coefficient D eff for water lies in the range 10 −11 to 10 −14 m 2 s −1 .…”

An Easy Fabricable Film for Organic Electronics Based on Phenoxy and Epoxy

“…In the PET polymer, terephthalate contains two electronegative oxygen atoms on an ester group, which are the probable cause of the swelling of the PET. [44] In the case of PE polymer, the OH from phenoxy and the OH from epoxy after the cure are the main reasons for the polymer swelling. [45,46] The barrier properties of the films were calculated by the MPR method as shown in Figure 8b.…”