A facile and controllable synthesis of dual‐crosslinked elastomers based on linear bifunctional polydimethylsiloxane oligomers

Abstract

Dual‐crosslinked supramolecular elastomers with the hybrid network consisting of hydrogen bonds and covalent bonds combine the reversibility of hydrogen bond and mechanical properties of covalent crosslinking network. In this article, isocyanate mixture is used as curing agent to prepare dual‐crosslinked elastomer based on bifunctional polydimethylsiloxane under mild condition. This method can effectively build up a hybrid network with the designed structure. A series of elastomers with same hydrogen bond density and variable covalent crosslinking degree are obtained. Swelling measurements and 1H‐NMR spectra confirm the feasibility and controllability of curing method, the increasing of bifunctional isocyanate give rise to higher covalent crosslinking degree, improving the solvent resistance. The studies on viscoelastic property show that the introduction of an irreversible covalent crosslinking network stabilize the hybrid network, restrain the chain movement. The mechanical and self‐healing property studies reveal that the covalent crosslink significantly reinforce the whole network, while the reparable strength seems to mainly depend on the hydrogen bond density. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3760–3768

Elastomer Reinforced with Innate Sulfur-Based Cross-Links as Ligands

“…Specifically, with 2.05 wt % Cu 2+ and 1.98 wt % Fe 3+ , the tensile strength and toughness of SS7-Cu1/Fe3 are 18.87 ± 1.25 MPa and 14.18 ± 0.67 MJ/m 3 , respectively, which are 6- and 5-fold that of SS7, respectively. Notably, the modulus (stress at 200% strain) of SS7-Cu1/Fe3 reaches 12.72 ± 0.47 MPa, which is unprecedented when compared with reported elastomers reinforced by sacrificial bonds or nanofillers. ,− Figure b compares the moduli for reported elastomers reinforced by sacrificial bonds with that in this work. Herein, elastomers with a T g higher than ambient temperature (20 °C) are excluded in the comparison because plastic behavior is dominant in those systems.…”

Effect of Metal-Ligand Coordination Complexes on Molecular Dynamics and Structure of Cross-Linked Poly(dimethylosiloxane)

“…Further analysis of DSC measurements for bpyPDMS-Me(II) materials allowed to state that T g for all complexes is around 150 K [ 23 ], which is similar to bpyPDMS. Therefore, it can be concluded that complexing by using chosen metal ions has no influence on T g value of final complexes.…”

“…Polymers 2020, 12, x FOR PEER REVIEW 3 of 16 with a complex structure, the key aspect is to define and correctly assign the molecular relaxations and transitions with regard to chemical composition, as well as describe their influence on the operational parameters. According to our best knowledge, only a few studies have been reported for PDMS-based complex materials, and they have concerned an examination of viscoelastic properties (complex modulus), done by dynamic mechanical spectroscopy [23,24].…”

“…One of the most popular elastomers commonly used in this area is cross-linked poly(dimethylosiloxane) (PDMS). Moreover, PDMS is characterized by the lowest T g~1 53 K among polymers, is not expensive and susceptible to chemical materials, and they have concerned an examination of viscoelastic properties (complex modulus), done by dynamic mechanical spectroscopy [23,24].…”

Viscoelastic and self-healing behavior of silica filled ionically modified poly(isobutylene-co-isoprene) rubber

“…This included materials like natural rubber, [2][3][4] chloroprene rubber, 5 polybutadiene, 6 acrylonitrile butadiene rubber, 7 styrene butadiene rubber, 8 and polydimethylsiloxane. 9,10 In order to facilitate self-healing, both physical [6][7][8][9] and reversible covalent crosslinking [2][3][4][5] have been utilized in these rubber systems, with strong focus on the basic principles of self-healing. In recent publications, the self-healing behavior of rubber composites has met increasing interest in materials research.…”