Research Article
Development and Characterization of Fiberglass/Sponge Gourd Hybrid Composites: Effect of Water Absorption on the Elastic Behavior and Impact Strength
Ronaldo Gomes de Castro Medeiros
,
José Roberto Moraes d’Almeida*
Issue:
Volume 15, Issue 4, December 2026
Pages:
132-147
Received:
8 September 2026
Accepted:
23 September 2026
Published:
23 October 2026
Abstract: Polymer matrix composites reinforced with lignocellulosic fibers have been gaining importance in various applications. However, the environment to which the composite will be exposed can significantly influence its behavior, and humid environments can be potentially aggressive. There are few studies on the microstructural characteristics and mechanical behavior of hybrid composites with sponge gourd and glass fibers, and the effect of moisture absorption and temperature on their behavior is still little explored. Therefore, in this work, aging tests were performed on glass fiber and sponge gourd fiber composites, as well as on their hybrid composite, by immersion in distilled water at two aging temperatures (25°C and 60°C). The mechanical behavior of aged and unaged samples was evaluated through destructive impact test and non-destructive impulse excitation test. The water absorption process was also evaluated and characterized by determining the diffusion coefficients and moisture saturation values. The impact test results allowed for the identification of failure modes and the evaluation of the effect of water absorption between the two different aging temperatures. The glass fiber composites showed little variation in impact strength before and after aging. However, the sponge gourd and hybrid composites showed considerable variation in impact strength after aging. Hybridization, however, proved efficient, and the hybrid composites exhibited impact resistance superior to that of the sponge gourd composites, even after aging. Non-destructive testing allowed for the evaluation of the aging effect on Young's modulus and loss factor. Results for the hybrid composites showed that hybridization efficiently protected the sponge gourd fibers and significantly reduced the degradation of the sponge gourd composite, in addition to providing a more environmentally friendly design alternative.
Abstract: Polymer matrix composites reinforced with lignocellulosic fibers have been gaining importance in various applications. However, the environment to which the composite will be exposed can significantly influence its behavior, and humid environments can be potentially aggressive. There are few studies on the microstructural characteristics and mechan...
Show More
Review Article
Conversion of Microfibers to Cellulose Nanofibers (CNF) for High-performance 3D Printing Composites: A Review
Issue:
Volume 15, Issue 4, December 2026
Pages:
148-160
Received:
30 September 2026
Accepted:
26 October 2026
Published:
12 November 2026
DOI:
10.11648/j.am.20261504.12
Downloads:
Views:
Abstract: The global transition toward a circular bio-economy has positioned Cellulose Nanofibers (CNF) as a premier sustainable alternative to petroleum-based reinforcements in additive manufacturing. This review provides a comprehensive meta-analysis of the "top-down" conversion of hierarchical microfibers into individualized nanofibers and their subsequent integration into high-performance 3D printing composites. We evaluate the synergistic effects of chemical pretreatments, specifically TEMPO mediated oxidation and acetylation on fiber morphology and interfacial compatibility. Multi-instrumental screening data revealed that while mechanical disintegration alone is energy-prohibitive >20,000 kWh/t, TEMPO-oxidation facilitates the liberation of nanofibers with ultra-high aspect ratios and uniform diameters of 3-5 nm at significantly reduced energy inputs. FTIR and XRD analyses confirm the successful substitution of hydrophilic hydroxyl groups without compromising the Cellulose I crystalline core, a critical factor for dispersion in hydrophobic polymers like PLA, ABS, and PP. Furthermore, we analyze the rheological and thermal bottlenecks of 3D printing; TGA and DTA results indicate a narrowed processing window 220°C for modified CNFs, while DMA profiling demonstrates a 25–40% increase in storage modulus above the glass transition temperature (Tg), effectively extending the structural utility of bio-polymers. The review concludes by identifying the "Future Scope" of the field, highlighting the need for solvent-free grafting techniques and thermal robustification to enable the next generation of industrial-scale, bio-reinforced additive manufacturing.
Abstract: The global transition toward a circular bio-economy has positioned Cellulose Nanofibers (CNF) as a premier sustainable alternative to petroleum-based reinforcements in additive manufacturing. This review provides a comprehensive meta-analysis of the "top-down" conversion of hierarchical microfibers into individualized nanofibers and their subsequen...
Show More
