Understanding the Interfacial Adhesion between Natural Silk and Polycaprolactone for Fabrication of Continuous Silk Biocomposites

Abstract

The poor interfacial adhesion between silk fiber and polyester species remains a critical problem for the optimal mechanical performance of silk-reinforced polyester composites. Here, we investigated in quantitative terms the interfacial properties between natural silk fibers and polycaprolactone (PCL) at nano-, micro-, and macroscales and fabricated continuous silk-PCL composite filaments by melt extrusion and drawing processing of PCL melt at 100, 120, and 140 °C. Bombyx mori (Bm) silk, Antheraea pernyi (Ap) silk, and polyamide6 (PA6) fiber were compared to the composite with PCL. The Ap silk exhibited the highest surface energy, the best wettability, and the largest interfacial shear strength (IFSS) with PCL. The silk-PCL composite from the 120 °C melt processing displayed the highest tensile modulus, implying an optimal temperature for interfacial adhesion. The Raman imaging technique revealed in detail the nature of the physical fusion of the interface phase in these silk-and polyamide-reinforced PCL composites. This work is intended to lay a foundation for the design and processing of robust composites from continuous silk fibers and bioresorbable polyesters for potential structural biomaterials.

Silk Fibroin-Based Triboelectric Nanogenerators for Energy Harvesting and Biomedical Applications

“…72,73 Its surface chemistry and molecular structure promote intimate contact and adhesion with various substrates, facilitating efficient charge transfer and triboelectric coupling. 74 This intrinsic compatibility streamlines the integration of SF into TENG designs, allowing for the formation of stable frictional pairs with other materials. As a result, SF-TENGs demonstrate enhanced energy harvesting capabilities and broader application potential in nanotechnology.…”

“…SF exhibits favorable interfacial interactions and compatibility with materials commonly used in TENG fabrication. , Its surface chemistry and molecular structure promote intimate contact and adhesion with various substrates, facilitating efficient charge transfer and triboelectric coupling . This intrinsic compatibility streamlines the integration of SF into TENG designs, allowing for the formation of stable frictional pairs with other materials.…”

A review of the effect of hydrothermal aging on the mechanical properties of 2D fiber‐reinforced resin matrix composites

“…Natural fibers offer significant advantages in reinforcing polymer composite 102–105 . However, long‐term outdoor applications pose a challenge in maintaining the mechanical stability of composites under hot and humid conditions.…”

“…The data shows that the Natural fibers offer significant advantages in reinforcing polymer composite. [102][103][104][105] However, long-term outdoor applications pose a challenge in maintaining the mechanical stability of composites under hot and humid conditions. Kafodya et al 106 conducted a study on the mechanical properties of unidirectional flax fiber-reinforced phenolic (FFRP) composites after aging for 3 years in distilled water at three different temperatures (23 C, 37.8 C, and 60 C).…”

Restructuring the Interface of Silk–Polycaprolactone Biocomposites Using Rigid-Flexible Agents

“…Polycaprolactone (PCL) is among the most used biodegradable polymers, which has the advantages of a low melting point, high extensibility, and good plasticity/processibility, making it an attractive matrix for biomedical composites. − However, natural fiber-reinforced PCL composites are limited by the poor interfacial adhesion between the fiber and the matrix . Physical and chemical surface modifications on fibers have been utilized to enhance the interfacial adhesion between natural fibers and the polymeric matrix. , For example, plasma treatment could enhance the mechanical interlocking between cellulose fibers and thermoplastic matrices; chemical grafting and etching could improve adhesion via covalent bonds and other molecular interactions.…”