Effect of natural rubber on wood‐reinforced tannin composites

Abstract

Natural rubber latex was added to composite materials formulated from a quebracho tannin adhesive crosslinked with hexamethylenetetramine and wood flour as a reinforcing filler. The final microstructure of the thermoset modified by the addition of different concentrations of latex was observed by scanning electron microscopy. The flexural and impact behavior of the modified materials was analyzed and related to the final microstructure of the composites. The effect of exposing the materials to humid environments was also evaluated. The measurements indicated that the addition of latex did not significantly reduce water absorption. However, it facilitated the preparation process of samples with low filler contents because of the increased viscosity of the mixture, which inhibited particle settling. On the other hand, the flexural properties increased with the addition of latex-containing proteins through a reaction similar to tanning in leathers. The impact properties presented a similar trend, with the largest change occurring between 0 and 5% natural rubber in the matrix formulation.

Effect of gamma radiation on physico-mechanical properties of vulcanized natural rubber/carbon fiber composites

“…The dry weight of NR consists of more than 90% of cis-1,4-isoprene (weight-average molecular weight = 4106 Da) and less than 10% of nonrubber constituents, like proteins, lipids, carbohydrates, resins, and inorganic salts. 7 Despite the development of chemosynthetic rubbers, NR is still produced in large amounts (107 tons year 1 ) from the rubber tree Hevea brasiliensis and is used for the production of automobile and aircraft tyres, latex gloves, hoses, belts, and so on. Natural rubber has been the most widely accepted rubbery material because of its excellent gum strength, elasticity, and low-temperature performance.…”

Oil palm microcomposites: Processing and mechanical behavior

“…They concluded that an increase in fiber loading can create a reduction in tensile and tear strength but an increment in the modulus of the composites. Effect of NR on wood‐reinforced tannin composites were done by Mosiewicki et al [14]. The modified materials exhibit substantial increase in mechanical properties.…”

Comparative experimental studies of phosphate glass fiber/polypropylene and phosphate glass fiber/natural rubber composites

“…NR is a biodegradable polymer and consists of mainly cis -1,4-isoprene and minor amounts of nonrubber constituents. 31 Leaching out of nonrubber materials occurred within a short time, but long-time immersion caused degradation of isoprene units and thus much weight loss was found for glass fiber/NR composites compared with that of the glass fiber/PP composites. NR is a natural biodegradable material.…”