Improved Toughness in Lignin/Natural Fiber Composites Plasticized with Epoxidized and Maleinized Linseed Oils

Abstract

The use of maleinized (MLO) and epoxidized (ELO) linseed oils as potential biobased plasticizers for lignin/natural fiber composites formulations with improved toughness was evaluated. Arboform®, a lignin/natural fiber commercial composite, was used as a reference matrix for the formulations. The plasticizer content varied in the range 0–15 wt % and mechanical, thermal and morphological characterizations were used to assess the potential of these environmentally friendly modifiers. Results from impact tests show a general increase in the impact-absorbed energy for all the samples modified with bio-oils. The addition of 2.5 wt % of ELO to Arboform (5.4 kJ/m2) was able to double the quantity of absorbed energy (11.1 kJ/m2) and this value slightly decreased for samples containing 5 and 10 wt %. A similar result was obtained with the addition of MLO at 5 wt %, with an improvement of 118%. The results of tensile and flexural tests also show that ELO and MLO addition increased the tensile strength as the percentage of both oils increased, even if higher values were obtained with lower percentages of maleinized oil due to the possible presence of ester bonds formed between multiple maleic groups present in MLO and the hydroxyl groups of the matrix. Thermal characterization confirmed that the mobility of polymer chains was easier in the presence of ELO molecules. On the other hand, MLO presence delayed the crystallization event, predominantly acting as an anti-nucleating agent, interrupting the folding or packing process. Both chemically modified vegetable oils also efficiently improved the thermal stability of the neat matrix.

Effect of Almond Shell Waste on Physicochemical Properties of Polyester-Based Biocomposites

“…Effectiveness of maleinized linseed oil has been demonstrated in composites based on lignin fillers and, specifically, from ground almond shells and some biodegradable polymers, such as poly(lactic acid) (PLA) and lignin. In this case, the poor result obtained with the INZEA matrix should be attributed to the particular composition of the commercial biopolymer used (a bio-based blend mainly composed of a polyester matrix) [30,39,40]. Joncryl ADR 4400 added to the formulation with fine particles INZEA_10ASF_1J produced an increase in flexural strength from 44 to 48 MPa.…”

Improvement of Toughness and Mechanical Properties of Furfurylated Wood by Biosourced Epoxidized Soybean Oil

“…When the content of ESO increased to 50 wt %, the hardness of the modified wood decreased more sharply than that of W FA , and the values of the mechanical properties of W FA−ESO-50 were lower, which was consistent with the findings of previous studies. 41 Adding an appropriate amount of ESO effectively improved the wood mechanical properties.…”

Development of renewable thermosetting polymers based on grape seed oil derivatives

“…51 In addition, the elongation break was also higher than the values found by Domicini and coauthors when reacted the composite arboform with epoxidized vegetable oil or maleinized linseed oil (they did not use both monomers together). 34 Although the catalyzed polymers prepared from catalyzed reactions were harder than that from the noncatalyzed reaction, all the polymers can be considered as soft materials with the noncatalyzed system possessing a higher ductility compared to the catalyzed. This effect can be attributed to the long chains of triglycerides, present in both monomers.…”

“…[27][28][29] Other papers used maleinized vegetable oils together with other epoxidized monomers as hardeners. [30][31][32][33][34] However, there are no previous reports of a polymer prepared using only the maleinized oil reacting with an epoxidized oil. As consequence, the present paper describes the use of both EGSO and MGSO to produce new biopolymers.…”