Projects / Programmes
Correlation between amorphous phase of PET fibers and oligomer content
| Code |
Science |
Field |
Subfield |
| 2.14.00 |
Engineering sciences and technologies |
Textile and leather |
|
| Code |
Science |
Field |
| T470 |
Technological sciences |
Textiles technology |
amorphous phase, polyester, oligomers, dry annealing, wet annealing, restricted, unrestricted
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
20045 |
PhD Petra Kovačič |
Textile and leather |
Head |
2007 - 2009 |
43 |
Organisations (1)
Abstract
Research is based on investigation of new production processes of clean polyester processing. The problem of oligomer migration From PET during high temperature hydrotermical processes was well solved with alkaline pretreatment (SI Patent No. 21189). Further investigation showed that we can influence the oligomer migration during acid HT dyeing with changing stabilization conditions. Results are captured in patent application P – 200600079 together with factory Velana, where new procedure is already in use. We found out that stabilization temperature (190 - 210 °C) did not change the crystalline structure of PET significant. We concluded that the reason for oligomer migration to the surface of PET must be in the amorphous phase of fibers. The most reliable method for determination of changes in amorphous regions is still diffusion of disperse dyes in fibers. On the assumption that dyeings lasted short time and that diffusion coefficient is independent of dye concentration, the results of time dependent dyeing with disperse dyes at high temperature (130 and 135 °C), evaluated using parabolic law, will be essential for evaluation of diffusion coefficient of disperse dyes in polyester fabrics stabilized at different temperatures. Simultaneous evaluation of the quantity and composition of oligomers will be even more important.
We want to determine how the changes in amorphous regions (due to temperature of stabilization), regardless to historical processes of PET fibers, influence the oligomer migration. In this research we do not want to be limited to industrial stabilization conditions, but we also want to research the influence of annealing under dry and wet conditions at broader temperature interval and under rigorous conditions.
We will be investigating changing of structure of PET fibers very preciselly after stabilization at different conditions (temperature, time and tension) and we will try to find a corelation between gravimetrically determined oligomer content and structural changes. We will focus particulary on amorphous phase of fibers. We will use methods, which are used for determination of changes in amorphous phase directly or indirectly. This research is basic research that has very important applicable meaning.
Significance for science
In this research structural changes of PET fibers during stabilization at different condition (temperature, time, and tension) has been investigated. The main goal of the research was to find correlation between oligomer content and structural changes. Gel permeation cromatography was used to determine the composition of extracted oligomers as we wanted to know how structural changes of PET fibers affect the cyclic trimer migration.
Research results lead us toward new theoretical knowledge about correlation between oligomer content and structural changes of PET fibers. Correlation between K/S values of PET dyeings and oligomer content is very interesting.
Significance for the country
The research results show that with different stabilization conditions we can affect the structural changes of PET fibers and further on the reduction of oligomer migration which causes many problems Slovene and foreing producers of PET textiles. To be competetive on the market, the producers are forced to buy cheap, less quality materials that cause even greater problems because of oligomer migration. Therefore we think that present research have an important contribution to social - economical development of Slovenia as it would help to maintain jobs in textile industry. Problems with oligomer migration during PET processing present in addition to financial also environmental and health problem.
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