Maleated polypropylene as coupling agent for polypropylene composites reinforced with Eucalyptus and Pinus particles

Abstract

Waste from the processing of hardwood and coniferous wood generated in the timber industries is difficult to dispose of and can cause considerable environmental impacts, such as soil and groundwater contamination. In this context, composites with varying concentrations of polypropylene, maleated polypropylene, and particulate Eucalyptus and Pinus waste were produced in a twin screw extruder and injection molded as test bodies for tensile and flexural tests. The morphology of the composites was investigated via scanning electron microscopy. The thermal properties were identified through differential scanning calorimetry. The tensile and flexural results for the two waste formulations indicated that the addition of vegetable fillers increased the modulus of elasticity and bending, and the compatibilizer provided increased resistance to stress and maximum deflection. The scanning electron micrographs illustrated the wetting of the cellulosic charge by the thermoplastic polymer with the compatibilizer, which corroborated the possible occurrence of an esterification reaction and hydrogen bonding interactions in the matrix-particle interface. The incorporation of waste in the composite resulted in the reduction of the degree of crystallinity of polypropylene, regardless of the use of the compatibilizer. This was explained by the barrier capacity of the charge, which prevented the growth of the crystals.

Using furniture factory waste sawdust in wood-plastic composite production and prototype sample production

“…The TS values decreased with the increase of the FFWS filler addition into the polymer matrix, but an increase was observed in the TS values with the addition of MAPP. Similar results have been reported in previous studies (Yang et al 2004;Yang et al 2007;Bledzki and Faruk 2013;Maziero et al 2019;Çavuş 2020;Çavuş and Mengeloğlu 2020;Başboğa et al 2022).…”

“…In WPC production, the ratio of lignocellulosic filler should be kept low in the injection method compared to the extrusion method. In the literature studies reviewed, it has been observed that the proportions of lignocellulosic fillers generally vary between 10% and 40% by weight (Yan et al 2013;Sullins et al 2017;Langhorst et al 2018;Maziero et al 2019;Çavuş 2020;Çavuş and Mengeloğlu 2020;Mengeloğlu and Çavuş 2020;Manaia and Manaia 2021;Vallejos et al 2023). Increasing the filler ratios decreases the melt flow index of the plastic.…”

“…Maleic anhydride-grafted polypropylene (MAPP) is one of the commonly used compatibilizers as a coupling agent (Çetin et al 2000;Shahzad 2011;Langhorst et al 2018;Çavuş and Mengeloğlu 2020;Çavuş 2020;Han et al 2021). It has been observed that the mixing ratios of coupling agents are used in the range of 2 to 10%, and optimum properties are often achieved in the range of 3 to 5% (Çetin et al 2000;Panthapulakkal and Sain 2007;Langhorst et al 2018;Maziero et al 2019;Díaz et al 2020;Başboğa et al 2022;Vallejos et al 2023). Considering these findings, in the present study, MAPP was used at 0% and 3% by weight.…”

Utilization of Wood Flour from White Oak Branches as Reinforcement in a Polypropylene Matrix: Physical and Mechanical Characterization

“…In recent decades, researchers have added natural fibers (cellulose-based fibers) to polymeric matrices [9], such as hemp [10,11], sugarcane bagasse [12,13], corn stalk fiber [14], jute [10,15,16], sisal [10,15,17], lino [15], rice straw stem fibers [18], henequen [19][20][21], agave [22][23][24], palm [25], coconut [26], pine cone residues [27,28], and cotton [29], among others, and were the subject of different studies such as processing methods, mechanical characterization [28], and biodegradation [30,31], among others. To improve adhesion and mechanical properties, compatibilizers [24,[32][33][34][35] and chemical modifications of natural fibers have been used [32,[36][37][38].…”

“…These materials have significant advantages over wood, since, in addition to being lighter, they are more resistant to humidity, have greater dimensional stability, and are resistant to biodegradation caused by insects, bacteria and fungi, mainly at low reinforcement concentrations, and therefore have longer useful lifetimes [31]. Among the materials obtained from wood that have been used are pine particles [23,31,35], maple [31], oak [31,39], oyamel [12], eucalyptus [35,40,41], poplar [42], guaje [43], and birch [44]. These materials have been used mainly in the construction and automotive industries [45,46], being of particular interest because of their great potential for synergism in mechano-static properties.…”