Efecto en las propiedades mecánicas de una resina pinífera modificada biodegradable, al utilizarla como compatibilizante o acoplante en formulaciones elastoméricas sin o con fibra de agave y hule de poli(estireno-butadieno). Un paso hacia la formulación de elastómeros verdes

Abstract

In this work, the effectiveness of a biodegradable modified pine rosin (Amberyl MP-30 (A-30)), is evaluated as compatibilizer or coupling agent to substitute resorcinol (which is toxic and non-biodegradable) in elastomeric formulations. Their mechanical properties are compared vs formulations containing resorcinol-hexamethylenetetramine (R-HMT) in: a) styrene–butadiene elastomers (SBRs), and: b) SBR composites reinforced with discarded agave fibers. For the comparison as compatibilizer, equivalent formulations containing resorcinol or A-30 are prepared. Likewise, for the equivalent composites comparison, the coupling agent (R-HMT or A-30) and sulfur amount as crosslinking agent (2,5 parts per 100 rubber (phr), 7,5 phr or 15 parts per 100 phr) are varied. The Tensile tests at room temperature, and the mechanodynamic analysis using sweeps of temperature (from 70 °C to 40 °C) and frequency (from 0,4 Hz to 40 Hz), allowed the observation of moduli improvements (up to 74 % in Young modulus) and deformation capacity (up to 260 %) for the materials with A-30 over the materials where resorcinol was used. The better performance as compatibilizer or coupling agent of the A-30 was also shown with clarity in the morphological characterization, showing higher compacity in the formulated polymer matrix, and higher closeness between matrix and fibers, comparing with fractured samples using R-HMT. It has been shown here, that formulating rubbers or elastomeric composites with A-30 and HMT, can successfully substitute the R-HMT pair, because it works better as compatibilizer or coupling agent and is biodegradable. Agents of natural origin like this one, have a great potential to contribute to the development of elastomers and flexible composites that are environmentally friendly.