Cure Characteristics and Mechanical Properties of Pineapple Leaf Fibre Filled Natural Rubber

Abstract

The cure characteristics and mechanical properties of natural rubber filled with pineapple leaf fibre (PLF) were studied at different filler contents and particle sizes. The PLF was characterized for filler properties while carbon black (N330) served as the reference filler. The natural rubber vulcanizates were compounded on a two-roll mill. Results showed that PLF (300 µm) filled natural rubber vulcanizates exhibited the highest maximum torque (T max) (47.04 lb-in) at filler content, 10 phr among the filler particle sizes investigated. The minimum torque (T min) of the vulcanizates generally increased with the increase in filler contents and particle sizes. The scorch times of the rubber vulcanizates did not vary with fibre content while the cure times of PLF (300 µm) filled rubber vulcanizates decreased with filler content. The tensile strength (TS) of PLF (150 µm) filled natural rubber vulcanizates generally increased with the increase in filler content whereas the tensile modulus of the rubber vulcanizates decreased steadily with increasing filler particle size at filler contents, 5 and 30 phr. The elongation at break (EB) of the rubber vulcanizates exhibited no general order of variation with filler content and particle size, and was generally greater than that of unfilled natural rubber. The flexural strength of the rubber vulcanizates increased with increasing filler particle size at filler contents, 20 and 40 phr. The addition of PLF and carbon black improved the compression strength of the rubber vulcanizates, and which for PLF (300 µm) and CB fillers generally increased with the increase in filler content. The study has demonstrated the enhancement of properties of natural rubber vulcanizates on incorporation of PLF into natural rubber, however, the property enhancements obtained were less than those recorded for CB filled natural rubber vulcanizates.

Cure Behaviour and Tensile Properties of Pineapple Leaf Fibre Reinforced Natural Rubber Composites

“…In other words, the viscosity increases when the filler contents increase. Good fillerto-matrix adhesion is shown by the rise in 𝑀𝑀 𝐿𝐿 with greater filler content, which limits the free mobility of rubber chains [22]. Similar observation had been reported by Justyna Miedzianowska et al, [23].…”

“…𝑡𝑡 𝑠𝑠2 of the prepared NR compounds shows a decrease in trend up to 20 phr and slightly increase at 30 phr of PALF content. The decrease of 𝑡𝑡 𝑠𝑠2 with greater fibre content may be owing to fibre-related factors such as fibre surface reactivity, fibre surface area, and fibre particle size [22].…”

End-Use Properties of Pineapple Leaf Fibre Filled Natural Rubber

“…The present paper which is an extension of a previous report [19] presents results obtained on the end-use properties of pineapple leaf fibre filled natural rubber. The pineapple leaf fibre (PLF) sieved to 75, 150 and 300 µm particle sizes was used within filler contents, 0 to 40 phr.…”

“…The properties of the rubber vulca-nizates investigated were abrasion resistance, hardness, swelling index and specific gravity. In an earlier communication [19], PLF was used to compound natural rubber and the study showed that pineapple leaf fibre enhanced the tensile, flexural, compression strengths and tensile modulus of the natural rubber vulcanizates whereas the elongation at break of the unfilled natural rubber vulcanizate was greater than those of filled rubber vulcanizates. In Nigeria, pineapple leaves presently have no identifiable industrial applications and can be seen littering farm yards as wastes.…”

“…5) Pineapple leaf fibre used as filler in this study was prepared from pineapple leaves collected locally at Umuagwo, Nigeria. The pineapple leaf fibre was sieved to three particle sizes, 75, 150 and 300 µm and characterized for oil absorption (ASTM D 1510, 1983), moisture content (ASTM D1509-13), pH (ASTM D 1512-05), specific gravity and iodine adsorption according to standard methods and the results have been reported [19].The compounding and curing of the natural rubber vulcanizates were as described previously[19]. The abrasion resistance (ISO 4649 DIN) and hardness (ASTM D 2240) of the rubber vulcanizates were determined by standard methods.…”