Aug 2026· Macromolecules· 0 citations· 45 references
Abstract
The mechanical behavior of semicrystalline polymers is governed by the cooperative response of crystalline lamellae and interlamellar amorphous chains, yet how this ordered–disordered coupling regulates molecular-scale fracture remains poorly understood. Polymer lamellar single crystals offer a structurally defined platform to isolate elementary deformation and failure processes that are otherwise obscured in bulk hierarchical morphologies. Here, we investigate the crack propagation behavior in a polyethylene lamellar single crystal under tensile loading. Crack growth is found to proceed in a stepwise manner rather than propagating continuously through the ordered crystalline domain. Statistical analysis and lateral force microscopy reveal that crack arrest preferentially occurs near specific lamellar regions and is closely associated with changes in surface chain-folding orientation, demonstrating that even an ultrathin amorphous layer of only 1–2 nm can effectively suppress crack propagation. These findings highlight the amorphous fold surface as a key molecular factor governing crack propagation, offering insight into how local chain topology contributes to fracture resistance in semicrystalline polymers.
Grain boundary engineering is a major avenue for tailoring the mechanical behavior of polycrystalline materials. Grain boundary complexions, including amorphous intergranular films, are classically accessed through thermal driving forces and solute segregation. Here, we discover that plastic deformation can drive amorp...
M. Ahmadi, Jin Qin, Gabrielle Tiphéne et al.· 0 citations
Melt memory in semicrystalline polymers is the remarkable ability of polymer chains to retain structural information from a prior crystalline state after being heated above the melting temperature. This phenomenon can induce extraordinary self-nucleation and strongly influence crystallization kinetics and final materia...
A. de Nicola, A. Müller, Dario Cavallo et al.· Journal of the American Chem...· 0 citations
Polymer fracture is governed by plastic deformation around crack tips, yet its underlying molecular processes remain difficult to observe in amorphous polymers. Polyrotaxane glasses provide a rare opportunity to probe these processes because the orientation and intermolecular distance of the constituent ring molecule...
The morphology of nanoscale γ lamellae strongly influences the mechanical properties of fully lamellar Ti-Al alloys; however, the coarsening mechanisms governing these nanostructures remain poorly understood. This work combines phase-field simulations and experiments to investigate the growth and coarsening of γ lamell...
Wei-Dong Song, Ji-Cheng Zhuo, Yang Chen et al.· Science China Technological...· 1 citation
Topochemical reactions in molecular crystals are often accompanied by severe lattice strain, frequently leading to crystal fracture and loss of crystallinity. Here we report an unusual case in which heat-driven topochemical azide-alkyne cycloaddition (TAAC) polymerization in a non-centrosymmetric molecular crystal indu...
Bichu Sebastian, Kana M. Sureshan· Angewandte Chemie· 0 citations
Fully atomistic reactive molecular dynamics simulations were used to investigate how nanoscale cross-link heterogeneity affects the mechanical response and fracture behavior of DGEBA/33DDS epoxy networks. Epoxy models containing controlled low-cross-link regions were subjected to dynamic and quasi-static tensile defo...
