Temperature Scanning Stress Relaxation of an Autonomous Self-Healing Elastomer Containing Non-Covalent Reversible Network Junctions

Abstract

Abstract:In this work, we report about the mechanical relaxation characteristics of an intrinsically self-healable imidazole modified commercial rubber. This kind of self-healing rubber was prepared by melt mixing of 1-butyl imidazole with bromo-butyl rubber (bromine modified isoprene-isobutylene copolymer, BIIR). By this melt mixing process, the reactive allylic bromine of bromo-butyl rubber was converted into imidazole bromide salt. The resulting development of an ionic character to the polymer backbone leads to an ionic association of the groups which ultimately results to the formation of a network structure of the rubber chains. The modified BIIR thus behaves like a robust crosslinked rubber and shows unusual self-healing properties. The non-covalent reversible network has been studied in detail with respect to stress relaxation experiments, scanning electron microscopic and X-ray scattering.

Design Principles of Interfacial Dynamic Bonds in Self‐Healing Materials: What are the Parameters?

“…Taking the self-healing concept further, that centred around either extrinsic [52][53][54][55][56][57][58][59][60][61][62] or intrinsic mechanisms [63][64][65][66][67][68][69][70] or through intersection among the two approaches, [71][72][73][74][75] the interplay between thermodynamics, kinetics and transient relations in SH-PNCs are incredibly critical at the molecular level. The selfhealing materials that relays on extrinsic mechanism contains microcapsules reservoirs (hollow fibres, microvascular networks) as external healing agents, and the healing is triggered by slow release of healing agents from these capsules at the junction of the cut surface.…”

Recent advancements in self-healing polymers, polymer blends, and nanocomposites

“…In this system, healing agents undergo capturing in hollow fibers, 35 microspheres, 36 and other containing entities. 37 -40 During operation, a crevice or breakage propagated in the polymer results in the release of healing agents in the performance of the healing mechanism. The process of crack propagation and failure in a material is elucidated in Figure 8.…”

Assessing thermomechanical properties of a reactive maleic anhydride grafted styrene‐ethylene‐butylene‐styrene/thermoplastic polyurethane blend with temperature scanning stress relaxation method

“…Increase in TSSR index and crosslink density (CLD) gave a direct idea of the improved elasticity in the system with radiation curing. Das et al 12] conducted TSSR measurements in an autonomous self-healing elastomer with noncovalent reversible network junctions in modified bromobutyl rubber (BIIR). Barbe et al 11] in 2005 investigated modified styrene-ethylene-butylenestyrene (SEBS) via TSSR method.…”

“…The test was carried out in a TSSR instrument (Brabender GmbH, Duisberg, Germany, which is commercially available). [9,11,12,15] The TSSR instrument is equipped with an electrical heating chamber in which the sample to be tested is positioned between two clamps. A definite uniaxial extension was applied to the sample through a linear drive unit connected to the clamps.…”

“…Temperature scanning stress relaxation (TSSR) method developed recently by Vennemann and others [7][8][9] stands as an excellent solution to this. The TSSR method has been used by many other researchers [10][11][12][13][14] to effectively explain the stress relaxation phenomenon in TPEs. Unlike conventional isothermal stress relaxation tests where the temperature is constant, in TSSR it linearly increases with a fixed heating rate β, for example, β = 2 K/min.…”