Crystallization kinetics of polyethylene terephthalate. I. Isothermal crystallization from the melt

Abstract

SynopsisThe crystallization behavior of polyethylene terephthalate (PET) was investigated as a function of molecular weight, temperature of crystallization, and polycondensation catalyst system. A detailed analysis of the crystallization c o w has been made utilizing the Avrami expression. The crystallization rate constants and the Avrami exponents were calculated. The results show that the rate constant and the mechanism of crystalhation are dependent on the molecular weight, temperature, and the polycondensation catalyst system. The catalyst system often exhibits a more significant influence than the molecular weight in controlling the rate of crystallization of PET.

Modeling of solid-state polycondensation. I. Particle models

“…This assumption is based on the thermal diffusion times in the reactor pellets The particle model variables can be divided into cosity (IV)] effect on PET crystallization, data of Jabarin. 21 two types: those that are subject to diffusion and 5333 / 8E45$$5333 06-04-98 10:56:35 polaa W: Poly Applied 2); however, the concentrations are adjusted to between the solid and gas phases is assumed to be that in equilibrium with the gas phase concenaccount for the end groups and condensate being concentrated in the amorphous phase (assumptration (k m Å ϱ and f solid,v Å P gas,v ). This amounts to assuming that the mass transfer resistance is tion 1).…”

“…An increase in polydispersity means the ratio of the I.V. The data of Jabarin 21 were used to find the constants for eq. (6) (constants in Table VI).…”

Effect of nucleating agents on crystallization kinetics of PET

“…The results show that three nucleating agents can increase the crystallization rate of PET, the nucleating effect of the ionomer Na + is slightly better than that of the talc, SB has the most excellent nucleating effect for the crystallization of PET according to the same content of nucleating agent. Generally, for most of crystallization polymers, the value of Avrami exponent n was found to vary between 1 and 4, corresponding to various growth forms from rod-like to sphere-like [4,19]. The Avrami model lumps together the formation of nuclei and their subsequent growth.…”

Relationship between Polyester Quality and Processability: Hands‐On Experience

“…According to Jabarin [3], the crystallization behavior is a function of the catalyst system employed and can be influenced by additional aspects of the polymer process which are still largely unidentified. Particularly in high-speed spinning, increased stress and molecular orientation in the skin layers could be observed with increasing crystallization rate as well as degree of crystallinity.…”