Influence of Mercerization on the Physical and Mechanical Properties of Polymeric Composites Reinforced with Amazonian Fiber

• Published in: Fibers and polymers Vol. 22; no. 7; pp. 1950 - 1956
• Main Authors: Giacon, Virginia Mansanares, Rebelo, Viviane Siqueira Magalhães, dos Santos, Gabrielle Machado, Sanches, Edgar Aparecido, Fiorelli, Juliano, dos Santos Costella, Ângela Mari, de Melo, Gabriel Messias Medeiros, Brito, Luiz Matheus Abecassis Ferreira
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Fiber Society 01-07-2021; Springer Nature B.V; 한국섬유공학회
• Subjects: Aging (natural); Bonding strength; Chemistry; Chemistry and Materials Science; Composite materials; Design of experiments; Fibers; Heat conductivity; Heat transfer; Mechanical properties; Mercerization; Paper board; Physical properties; Polymer Sciences; Polyurethane resins; Regular Articles; Swelling; Thermal conductivity; Thermoforming; 섬유공학; Mercerization; Screw withdraw strength; Polymeric composites; fibers; Castor oil
• DOI: 10.1007/s12221-021-0460-9
• EISSN: 1875-0052
• ISSN: 1229-9197

Natural fiber has been an attractive alternative as reinforcement in polymeric composites. However, their physical properties can be impaired due to the hydrophilic behavior of the vegetal fibers: the weak bonds at the interface fiber/matrix emerge due to the hydrophobic behavior of some polymeric matrices. This paper aims to evaluate the influence of mercerization process in
Leopoldinia piassaba
fibers on the physical, mechanical, thermal, morphological, and accelerated aging properties of polyurethane (PU)-based composites produced by the thermoforming process. The experimental design (2
2+1
) was applied considering the parameters NaOH Treatment and %(PU)Resin. The NaOH Treatment consisted of 5 % and 10 % NaOH solution for fibers mercerization, and %(PU)Resin consisted of different amounts of PU (15 %, 17.5 % and 20 %). The mercerization process chemically modified the interface fiber/matrix and improved the resistance of the composite to screw withdraw strength, ranging from 573 N to 1019 N, and from 574 N to 1648 N considering Surface and Top, respectively. According to Scanning Electron Microscopy (SEM) analysis, the mercerization process also improved the fiber/matrix adherence and reduced pores, resulting in swelling decreasing and thermal conductivity increasing. Furthermore, the mean thickness swelling (TS) value ranged from 6 to 15 % and was not statistically different after accelerated aging. The developed composites containing untreated fibers showed thermal conductivity values similar to the commercial medium density fiberboard (MDF).