Viscose fiber/polyamide 12 composites: Novel gas‐phase method for the modification of cellulose fibers with an aminosilane coupling agent

The objective of this study was to improve the adhesion between viscose fibers and polyamide 12 and, thereby, the mechanical properties of the corresponding composites. The cellulose fiber surface was chemically modified in the vapor phase with a silyl coupling agent, aminosilane [(3‐aminopropyl) triethoxysilane]. This new gas‐phase treatment for cellulose fibers proved to be highly effective. Relative to composites without the coupling‐agent treatment, the tensile strength of the composites (40/60 wt % fiber/polymer) increased from 49.3 to 87.4 MPa; the improved adhesion between the fibers and matrix induced by the coupling agent was observed under a scanning electron microscope. The presence and bonding of the coupling agent on the fibers after the reaction was confirmed by solid‐state 29Si‐NMR.