Enhancing Water Resistance in Cationic Cellulose Nanofibril Adhesive with Natural Rubber Latex

Abstract

Adhesives prepared with renewable materials through environmentally friendly processing offer an appealing alternative to their petroleum-based counterparts. Herein, we evaluated the adhesive properties of cationic cellulose nanofibrils (CCNFs) under dry and wet conditions and after mixing with natural rubber latex (NRL). Uniaxial tensile tests of negatively charged substrates (paper, aluminum (Al), and polypropylene (PP)) bonded with CCNF show a maximum lap shear strength that approached the failure point of the substrates, indicating the formation of a robust adhesive joint. The wet adhesion of CCNFs was improved (53% for PP and 154% for Al) by simple aqueous mixing with NRL suspension. This straightforward methodology promotes controlled CCNF and NRL electrostatic assembly that reduces the swelling of nanofibrils by water and improves adhesive cohesion. Cryogenic transmission electron microscopy images of CCNF/NRL complexes reveal that NRL particles are coated by a fibrillar CCNF network, providing morphological evidence that cationic nanofibrils contribute to interfacial adhesion to the solid substrates, while NRL enhances water resistance. This study presents a simple method to control noncovalent interactions and prepare nanocellulosebased adhesives with good mechanical properties and improved water resistance that are suitable for developing adhesives for different fields.

Enhanced Gas and Plasticizer Barrier Properties of Silicone Rubber with Ordered Functionalized Magnetic Graphene Oxide

“…Rubber composites have been widely used in various fields such as aerospace, chemical protective equipment, and sealing rings due to their high elasticity, great barrier performance, and excellent compressibility recovery. − In particular, silicone rubber (SiR) stands out as a polymer with remarkable properties such as high-temperature resistance, chemical corrosion resilience, excellent insulation capacity, and flexibility − making it an ideal material for the insulation layer of solid rocket motors (SRM). The SRM is composed of the shell, insulation layer, liner, and propellant grain from outside to inside. , The insulation layers play a key role in ensuring the safety and stable running of the SRM. , However, the intrusion of external gases will accelerate the aging of the insulation layer during long-term storage, which will progressively damage the reliability and service life of the insulation layer.…”