Meltable copolymeric elastomers based on polydimethylsiloxane with multiplets of pendant liquid-crystalline groups as physical crosslinker: a self-healing structural material with a potential for smart applications

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F20%3A00531985" target="_blank" >RIV/61389013:_____/20:00531985 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/20:10424680

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0014305720316761?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0014305720316761?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.eurpolymj.2020.109962" target="_blank" >10.1016/j.eurpolymj.2020.109962</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Meltable copolymeric elastomers based on polydimethylsiloxane with multiplets of pendant liquid-crystalline groups as physical crosslinker: a self-healing structural material with a potential for smart applications

Popis výsledku v původním jazyce

Elastomers with strong physical crosslinks were prepared, based on alternating polydimethylsiloxane (PDMS) spacer segments and pendant quartets of mesogenic building blocks (LC) of azobenzene type. They are structurally related to the well-studied polymers with pendant-chain LC units (light-sensitive actuators), but are generally highly different: The LC units make up only a small volume fraction in our materials and they do not generate elastic energy upon irradiation, but they act as physical crosslinkers with thermotropic properties. Our elastomers lack permanent chemical crosslinks – their structure is fully linear (with some dangling units). The aggregation of the relatively rare and spatially separated LC quartets (of small mesogen units) nevertheless proved to be an efficient crosslinking mechanism: The most attractive product displays a rubber plateau extending over 100 °C, melts near 70 °C and is soluble in organic solvents. The LC nano-aggregates were also found to be responsible for a continuous temperature region of phase transitions, e.g. two gel points observed by rheology. The physical crosslinks are reversibly disconnected by large mechanical strain at room temperature, but they undergo self-healing, also after sample disruption. The elastomers might be of interest for the development of passive smart materials (e.g. meltable rubbers for 3D-printing, or thermo-reversible visco-elastic mechanical coupling). Our study focuses on the comparison of physical properties and structure-property relationships in two systems, with long and with short PDMS spacer segments.

Název v anglickém jazyce

Meltable copolymeric elastomers based on polydimethylsiloxane with multiplets of pendant liquid-crystalline groups as physical crosslinker: a self-healing structural material with a potential for smart applications

Popis výsledku anglicky

Elastomers with strong physical crosslinks were prepared, based on alternating polydimethylsiloxane (PDMS) spacer segments and pendant quartets of mesogenic building blocks (LC) of azobenzene type. They are structurally related to the well-studied polymers with pendant-chain LC units (light-sensitive actuators), but are generally highly different: The LC units make up only a small volume fraction in our materials and they do not generate elastic energy upon irradiation, but they act as physical crosslinkers with thermotropic properties. Our elastomers lack permanent chemical crosslinks – their structure is fully linear (with some dangling units). The aggregation of the relatively rare and spatially separated LC quartets (of small mesogen units) nevertheless proved to be an efficient crosslinking mechanism: The most attractive product displays a rubber plateau extending over 100 °C, melts near 70 °C and is soluble in organic solvents. The LC nano-aggregates were also found to be responsible for a continuous temperature region of phase transitions, e.g. two gel points observed by rheology. The physical crosslinks are reversibly disconnected by large mechanical strain at room temperature, but they undergo self-healing, also after sample disruption. The elastomers might be of interest for the development of passive smart materials (e.g. meltable rubbers for 3D-printing, or thermo-reversible visco-elastic mechanical coupling). Our study focuses on the comparison of physical properties and structure-property relationships in two systems, with long and with short PDMS spacer segments.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

<a href="/cs/project/GA19-04925S" target="_blank" >GA19-04925S: Pokročilé inteligentní samoregenerující se nanokompozítní hydrogely citlivé na vnější podněty</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

European Polymer Journal

ISSN

0014-3057

e-ISSN

—

Svazek periodika

137

Číslo periodika v rámci svazku

15 August

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

23

Strana od-do

1-23

Kód UT WoS článku

000567604100020

EID výsledku v databázi Scopus

2-s2.0-85089956459