New insights into the molecular structure and dynamics of a recyclable and ionically crosslinked carboxylated nitrile rubber (XNBR)

Autor: Saul Utrera-Barrios, Reyes Verdugo Manzanares, Antonio Mattia Grande, Raquel Verdejo, Miguel Ángel López-Manchado, Marianella Hernández Santana
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Materials & Design, Vol 233, Iss , Pp 112273- (2023)
Druh dokumentu: article
ISSN: 0264-1275
DOI: 10.1016/j.matdes.2023.112273
Popis: Ionic crosslinking offers a route to rubber reprocessability due to ion pairs’ dynamism, with recent studies focusing on tensile properties recovery. However, this research aims to provide, for the first time, a comprehensive overview of the recyclability of carboxylated nitrile rubber (XNBR), spotlighting changes in molecular dynamics through multiple recycling cycles beyond tensile tests. A uniquely recyclable XNBR, incorporating ZnO as a multifunctional additive, was designed alongside a simple, scalable, two-step recycling process. Evidence of the delicate balance between crosslink density and molecular entanglements that affects the dynamics of the recycled material was found. Recycling also restricts the molecular dynamics near ionic domains; attributed to a higher crosslink density (from 3.69×10-5 mol cm−3 in the pristine sample to 6.00×10-5 mol cm−3 after the third cycle), caused by a decreased ionic clusters size (aggregation number drops from 12.2 to 6.9). Remarkably, negligible differences (
Databáze: Directory of Open Access Journals