Durability of lignocellulosic fibers treated with vegetable oil–phenolic resin

Jute and sisal fibers were treated with an aqueous emulsion of neem oil and phenolic resin at elevated temperature for enhancing their tensile strength, hydrophobicity and resistance against biological and chemical degradations. The process was found to lead to the transesterification of cellulose chain hydroxyl groups and increased crystallinity. Treatment efficacy was evaluated by characterizing fibers by exposing them to biological and chemical degradations. The results indicate that the short-term tensile strength increased by 61–75% following treatment. After biodegradation, treated fibers were found to retain 63–70% of their initial tensile strength, while untreated fibers retained 28–32%. Treated fibers retained 52–60% of tensile strength after 90-day exposure to 3% salinity and 48–55% of tensile strength after similar exposure to pH between 3 and 10. For untreated fibers the corresponding figures were 9–13% and 10–12% respectively.