Leather-like composite materials prepared from natural rubber and two leather wastes: Wet blue leather and finished leather

Abstract

In this study, leather-like composites were prepared from natural rubber (NR) and two different types of leather waste, namely wet blue leather (WBL) and finished leather (FL). Compounding was carried out on an internal mixer and two-roll mill, and curing was further conducted on a compression molding machine. The effects of leather type and content from 20 to 80 parts per hundred of rubber (phr) on cure characteristics, mechanical properties (hardness and tensile properties) and thermal stability of the as-prepared composites were investigated and compared with those of the unfilled NR compound. The curing rate and crosslink density of all composites were found to be lower than those of the unfilled NR. All WBL-filled NR composites exhibited higher tensile strength than the unfilled NR, while all FL-filled NR composites had lower values. Meanwhile, the hardness and modulus at 200% strain of all composites were increased with increasing leather waste contents compared to those of the unfilled NR. The composites containing low WBL loadings (20 and 40 phr) demonstrated higher elongation at break over the unfilled NR, while the other composites exhibited lower values. Besides, the thermal stability of all NR composites was deteriorated, but still largely retained.

On the Production of Poly(Lactic Acid) (PLA) Compounds with Metallic Stearates Based on Zinc, Magnesium and Cobalt. Investigation of Torque Rheometry and Thermal Properties

“…Poly (lactic acid) -PLA, coded Ingeo® 2002D, with a density of 1.24 g/cm 3 and melt flow index (MFI) = 5-7 g/10 min (210°C/2.16 kg), purchased from NatureWorks (Minnesota, USA). The pro-degradant additives used were: magnesium stearate -C 36 H 70 MgO 4 (D16y019), with purity higher than 99%; cobalt (II) stearate -C 36 H 70 CoO 4 (D13X021), salt of stearic acid with 9-10% cobalt, with purity higher than 99%; zinc stearate -C 36 H 70 ZnO 4 (557051), with purity higher than 99%.…”

“…Sustainability is a topic that has been applied with emphasis in different areas of the polymer transformation industry. [1][2][3] This concern emerges from a long evolution of the perception that industrial and human actions have negatively affected nature, especially with the inappropriate disposal of plastic products. [4][5][6] In this context, products derived from commodity polymers such as polypropylene (PP), polyethylene (PE), and polystyrene (PS) draw a lot of attention as a source of environmental pollution, both during the products processing and waste production, as well as the post-consumption by the population.…”

The Flexural Strength Prediction of Carbon Fiber/Epoxy Composite Using Artificial Neural Network Approach

“…The flexural strength of carbon fiber/epoxy resin composites is influenced by various variables, including ply orientation, the number of layers, manufacturing process, and the percentage of graphite filler. Among these variables, ply orientation and the number of carbon fiber layers are considered as primary factors that significantly impact the flexural strength and other mechanical properties [18][19][20][21][22][23]. In a study conducted by M. Ghasemi et al (2016) [18], polymer matrix composites (PMCs) using glass fiber/epoxy composites were subjected to thermal cycling, which involved varying temperature, ply orientation, volume of fiber, and the number of heating cycles.…”

Comparative study of three vulcanization kinetic models for natural rubber/leather wastes composites

“…Therefore, to understand the effects of adding post-industrial leather waste to natural rubber composites, it is important to know their physicochemical nature and the processes used to obtain them. 1-6…”

“…Therefore, to understand the effects of adding post-industrial leather waste to natural rubber composites, it is important to know their physicochemical nature and the processes used to obtain them. [1][2][3][4][5][6] During the vulcanization reaction, rubber compounds undergo alterations in some mechanical properties, such as hardness, resistance, and elastic modulus. By understanding this principle, it is possible to measure the change in the torque generated in the rubber composites as the vulcanization reaction takes place, i.e., as a function of time and at a set temperature.…”