Molecular weight and melting point values of PET monomer with hydroxyl groups [bis(2-hydroxyethyl)terephthalate (BHET)] are 254 and 109-110[degrees]C, respectively , Depending on these results obtained from DSC and end-group analysis, it can be said that WSCF-5 and WSCF-6 were mainly formed from BHET.
NMR analysis supports the formation of BHET for this product (WSCF-5).
The objective of the study was to achieve higher conversion of PET to BHET in reduced reaction time by means of reduced molecular mass of PET samples.
BHET was then separated by recrystallization, filtered, and dried in an air circulating oven at 60[degrees]C for 2 h.
The polycondensation of BHET
and DCDPS in ratio 1:1 in toluene was recorded in Fig.
NOMENCLATURE PET Polyethylene terephthalate TPA Terephthalic acid EG Ethylene glycol BHET
Bis(2-hydroxyethyl terephthalate) [M.
In the first step, BHET
separation from glycolysis products was optimized based on Taguchi's design of experiments.
2] atmosphere until all water evaporated and the BHET
monomer had melted.
The optimization of the copolytransesterification reactor is made in two steps: In the first step, both homopolytransesterification, between BHET
molecules, and copolytransesterification, between BHET
and POEG, reactions are taken into account.
C], the prehomopolytransesterification and precopolytransesterification reaction constants, based on the non-isothermal reaction of BHET
Tomita and Ida (15) also reported that, if less than 2 mol of EG are used, the degree of condensation of 2 to 4 are formed as well as BHET
These PETI copolymers had BHET
as major repeat units and BHEI units as a minor part.