A chemical modification-free strategy for fabricating tough and tear-resistant natural rubber/polysaccharide material

Natural rubber latex (NRL) is widely used in a variety of products, including gloves, balloons, condoms, and foamed items like pillows and footwear components. However, the limitations of traditional NRL materials in terms of tear resistance and toughness restrict their use in high-end applications. Hence, developing tough and tear-resistant NRL materials using eco-friendly and user-friendly methods remains highly desirable. In this work, a chemical modification-free method is reported for the fabrication of tough and tear-resistant vulcanized natural rubber/carrageenan material (SNR/KC). KC is introduced into NRL via a modified latex mixing strategy, which can form hydrogen bonds with the non-rubber components (NRC) such as proteins on the surface of natural rubber latex particles. As a result, KC can be well dispersed and form a segregated network structure within the rubber matrix. The rigid filler network created by KC effectively impedes crack propagation and enhances energy dissipation during deformation. Furthermore, the presence of KC in the NR matrix fosters the strain-induced crystallization (SIC) of NR. All these contribute to the superior tear resistance and toughness of composite materials. With only 0.1 phr of KC, the composite exhibits a fracture toughness of 208.4 kJ/m² and a tear strength of 50 kN/m. This work demonstrated that the interaction between polysaccharide and NRC of NRL can be leveraged to fabricate tough and tear-resistant NR composites without any chemical modification and tedious process, favoring a green development and high-quality pursuit of NRL materials.