Mechanical stability and degradation kinetics of a natural fiber biogeosynthetic composite from Typha domingensis and Boehmeria nivea under accelerated aging

Vollständiger Abstract

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Abstract Lignocellulosic biocomposites offer a renewable alternative to petroleum-derived materials, yet their photodegradation behavior under accelerated weathering remains insufficiently characterized from a reliability standpoint. This study evaluated the mechanical performance and degradation patterns of a laminar biotextile–biogrid biocomposite intended as a biodegradable geosynthetic analogue for short- to medium-term erosion-control and soil-protection applications. The material was assembled from a Typha domingensis core (leaf blades and basal sheath fibers, forming the fibrous biotextile) and a Boehmeria nivea (ramie) structural biogrid, both impregnated with castor oil-based polyurethane resin. Specimens were subjected to accelerated UV aging (water immersion, thermal cycling at 105 °C, and UV exposure per cycle) for 120 cycles, totaling 720 h of exposure (~ 570 h effective UV radiation). Tensile and puncture properties were quantified under uniaxial and multiaxial loading, and temporal trends were assessed through Generalized Linear Models, Generalized Estimating Equations, and Weibull reliability functions. Tensile strength remained stable throughout the aging program, maintaining a mean of 2.92 kN·m –1 , while strain capacity declined by 8.11% per 10 cycles, amounting to a cumulative loss of 60.6% and identifying ductility as the only photochemically sensitive property. Puncture resistance showed no significant temporal degradation, with coefficients of variation as low as 8.67% at 90 cycles compared with 10.3–44.9% for tensile parameters, reflecting more uniform failure behavior under multiaxial loading. Weibull reliability modeling yielded characteristic puncture strength of 1,784 N and 10th-percentile values of 1,078 N, with transient peak loads at 30 cycles. puncture resistance remained at or above the unaged control value at every exposure level, with a minimum retention of 98.4%, indicating functional adequacy within the tested laboratory exposure window.