How temperature-induced depolymerization and plasticization affect the process of structural relaxation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62690094%3A18470%2F24%3A50021142" target="_blank" >RIV/62690094:18470/24:50021142 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11150/24:10477725 RIV/00216275:25310/24:39922022

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0032386123008790?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0032386123008790?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.polymer.2023.126549" target="_blank" >10.1016/j.polymer.2023.126549</a>

Result language

angličtina

Original language name

How temperature-induced depolymerization and plasticization affect the process of structural relaxation

Original language description

The self-plasticization, i.e., the increase in the polymer segmental mobility by the inclusion of its own monomer, has a major impact on the structural, thermal, and mechanical properties of the polymer. Differential scanning calorimetry (DSC) was used to investigate the influence of thermally induced self-plasticization on the structural relaxation of polydioxanone (PDX). Depolymerization (based dominantly on the end-chain scission mechanism) was found to be controlled by the depolymerization temperature Td as well as the actual number of re-melting cycles (while keeping the time spent at Td constant). PDX samples with the glass transition temperature (Tg) ranging from-52 (highly plasticized) to-13 degrees C (virgin) were prepared. The DSC data were described in terms of the Tool-Narayanaswamy model; a consistent structural relaxation behavior associating the degree of plastici-zation with Tg was identified. The activation energy first decreased with plasticization from 430 kJ mol-1 to 210 kJ mol-1 in the Tg range of-40 to-13C, which is consistent with the plasticization-caused spacing-apart of the polymer chains resulting in larger free volume and increased freedom for the relaxation movements. For the highly plasticized PDX samples, the activation energy increased from 210 kJ mol-1 to 310 kJ mol-1, which appears to be associated with the possible segregation of the portion of the plasticizer into a discrete phase. The width of the relaxation times distribution increased with plasticization as a consequence of the plasticizer loosening the polymeric chains and enabling a wider variety of the segmental movement. The plasticization also leads to a higher dependence of the segmental relaxation movements on their current physico-chemical and steric surrounding.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10404 - Polymer science

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Polymer

ISSN

0032-3861

e-ISSN

1873-2291

Volume of the periodical

290

Issue of the periodical within the volume

January

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

"Article Number: 126549"

UT code for WoS article

001131270100001

EID of the result in the Scopus database

2-s2.0-85178091542