DOI: 10.4103/jioh.jioh_63_23 ISSN: 0976-7428
Flexural strength and hardness of short-silk fiber-reinforced composite with silane addition
Dyah A Widyasrini, Mutiara Annisa, Siti Sunarintyas, Harsini Harsini Abstract
Aim:
To investigate the optimum concentration of silane added in fiber-reinforced composites (FRCs) and its effect on flexural strength and surface hardness.
Methods and Material:
The degumming process was conducted by soaking the chopped Bombyx mori silkworm cocoons in Na2CO3 solution, hydrolyzing them with NaOH, and neutralizing them with hydrochloric acid. Then, lyophilization and ultra-sonification were carried out. Bombyx mori short-silk fibers (±1.49 µm) were placed into a silane solution with concentrations of 0%, 0.5%, 1%, and 1.5%. After silanation, fibers were mixed in a composite resin matrix. The volume fraction of the fiber used was 10%. Flexural strength and surface hardness tests employed 48 samples in beam and disc shapes, respectively. Each group included six samples. Flexural strength was tested using a universal testing machine and surface hardness using a microhardness tester in accordance with ISO 4049 (2000). Data obtained were analyzed statistically by analysis of variance (ANOVA), followed by a post hoc least significant difference test.
Results:
In the ANOVA test, a significant difference was found in the flexural strength and surface hardness among the four FRC groups (P < 0.05). In the post hoc test, the flexural strength of the FRC group with 0.5% silane was significantly different from other groups (P < 0.05). Meanwhile, the surface hardness of samples added with 0.5% silane was not significantly different from those added with 1% and 1.5% silane (P < 0.05).
Conclusions:
Thus, 0.5% silane might be the optimal concentration to obtain FRCs with appropriate flexural strength and surface hardness.