The Importance of Bulk Viscoelastic Properties in “Self-Healing” of Acrylate-Based Copolymer Materials

Zhao, Yuqi; Wu, Hanshu; Yin, Rongguan; Matyjaszewski, Krzysztof; Bockstaller, Michael R.

doi:10.1021/acsmacrolett.3c00626

“…The dependence of temperature, viscosity, and relaxation times for amorphous materials in the range of their T g was described by the Williams–Landel–Ferry (WLF) equation . As predicted by the WLF relationship and reiterated by recent studies, there is no question that the smaller the difference, the “softer” and less viscous polymers are. Does this imply that they are self-healable?…”

Section: Discussionmentioning

confidence: 99%

Dynamic Interfaces in Self-Healable Polymers

Liu,

Urban

2024

View full text Add to dashboard Cite

It is well-established that interfaces play critical roles in biological and synthetic processes. Aside from significant practical applications, the most accessible and measurable quantity is interfacial tension, which represents a measure of the energy required to create or rejoin two surfaces. Owing to the fact that interfacial processes are critical in polymeric materials, this review outlines recent advances in dynamic interfacial processes involving physics and chemistry targeting self-healing. Entropic interfacial energies stored during damage participate in the recovery, and self-healing depends upon copolymer composition and monomer sequence, monomer molar ratios, molecular weight, and polymer dispersity. These properties ultimately impact chain flexibility, shape-memory recovery, and interfacial interactions. Self-healing is a localized process with global implications on mechanical and other properties. Selected examples driven by interfacial flow and shape memory effects are discussed in the context of covalent and supramolecular rebonding targeting self-healable materials development.

show abstract

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

Gaikwad,

Urban

2024

Angewandte Chemie

0

View full text Add to dashboard Cite

Although F‐containing molecules and macromolecules are often used in molecular biology to increase the binding with Lewis acidic groups by introducing favorable C‐F dipoles, there is virtually no experimental evidence and limited understanding of the nature of these interactions, especially their role in synthetic polymeric materials. These studies elucidate the molecular origin of inter‐ and intra‐chain interactions responsible for self‐healing of F‐containing copolymers composed of pentafluorostyrene and n‐butyl acrylate units (p(PFS/nBA). Guided by dynamic surface oscillating force (SOF) and spectroscopic measurements supported by molecular dynamics (MD) simulations, these studies show that the reformation of σ‐σ orbitals in ‐C‐F of PFS and CH3CH2‐ of nBA units enables the recovery of entropic energy via flouorophilic‐σ‐lock van der Waals forces when PFS/nBA molar ratios are ~50/50. The strength of these interactions determined experimentally for self‐healable PFS/nBA compositions is in the order ~0.3 kcal/mol which primarily comes from flouorophilic‐σ‐lock (~70%) contributions. These interactions are significantly diminished for non‐self‐healable counterparts. Strongly polarized ‐C‐F σ orbitals create lateral dipolar forces enhancing the affinity towards ‐C‐H orbitals, facilitating energetically favorable interactions. Entropic recovery driven by non‐covalent bonding offers a valuable tool in designing materials with unique functionalities, particularly self‐healable batteries or other energy storage devices.

show abstract

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

Gaikwad,

Urban

2024

Angew Chem Int Ed

0

View full text Add to dashboard Cite

Although F‐containing molecules and macromolecules are often used in molecular biology to increase the binding with Lewis acidic groups by introducing favorable C‐F dipoles, there is virtually no experimental evidence and limited understanding of the nature of these interactions, especially their role in synthetic polymeric materials. These studies elucidate the molecular origin of inter‐ and intra‐chain interactions responsible for self‐healing of F‐containing copolymers composed of pentafluorostyrene and n‐butyl acrylate units (p(PFS/nBA). Guided by dynamic surface oscillating force (SOF) and spectroscopic measurements supported by molecular dynamics (MD) simulations, these studies show that the reformation of σ‐σ orbitals in ‐C‐F of PFS and CH3CH2‐ of nBA units enables the recovery of entropic energy via flouorophilic‐σ‐lock van der Waals forces when PFS/nBA molar ratios are ~50/50. The strength of these interactions determined experimentally for self‐healable PFS/nBA compositions is in the order ~0.3 kcal/mol which primarily comes from flouorophilic‐σ‐lock (~70%) contributions. These interactions are significantly diminished for non‐self‐healable counterparts. Strongly polarized ‐C‐F σ orbitals create lateral dipolar forces enhancing the affinity towards ‐C‐H orbitals, facilitating energetically favorable interactions. Entropic recovery driven by non‐covalent bonding offers a valuable tool in designing materials with unique functionalities, particularly self‐healable batteries or other energy storage devices.

show abstract

The Importance of Bulk Viscoelastic Properties in “Self-Healing” of Acrylate-Based Copolymer Materials

Cited by 6 publications

References 37 publications

Dynamic Interfaces in Self-Healable Polymers

Dynamic Interfaces in Self-Healable Polymers

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

Contact Info

Product

Resources

About