Chemical and Mechanical Characterization of Licorice Root and Palm Leaf Waste Incorporated into Poly(urethane-acrylate) (PUA)

Abstract

A poly(urethane-acrylate) polymer (PUA) was synthesized, and a sufficiently high molecular weight starting from urethane-acrylate oligomer (UAO) was obtained. PUA was then loaded with two types of powdered ligno-cellulosic waste, namely from licorice root and palm leaf, in amounts of 1, 5 and 10%, and the obtained composites were chemically and mechanically characterized. FTIR analysis of final PUA synthesized used for the composite production confirmed the new bonds formed during the polymerization process. The degradation temperatures of the two types of waste used were in line with what observed in most common natural fibers with an onset at 270 °C for licorice waste, and at 290 °C for palm leaf one. The former was more abundant in cellulose (44% vs. 12% lignin), whilst the latter was richer in lignin (30% vs. 26% cellulose). In the composites, only a limited reduction of degradation temperature was observed for palm leaf waste addition and some dispersion issues are observed for licorice root, leading to fluctuating results. Tensile performance of the composites indicates some reduction with respect to the pure polymer in terms of tensile strength, though stabilizing between data with 5 and 10% filler. In contrast, Shore A hardness of both composites slightly increases with higher filler content, while in stiffness-driven applications licorice-based composites showed potential due to an increase up to 50% compared to neat PUA. In general terms, the fracture surfaces tend to become rougher with filler introduction, which indicates the need for optimizing interfacial adhesion.

An efficient synthesis of bio-based Poly(urethane-acrylate) by SiO2-Supported CeCl3·7H2O–NaI as recyclable Catalyst

“…Catalyst screening and synthesis of NCO-terminated urethane prepolymer. Following our previous studies on the development of efficient and sustainable lactic acid polymerization [4], and synthesis of biomass-based PUA composite [5] we disclose a low-impact procedure for the synthesis of poly(urethane-acrylate). Several cerium-based catalysts were tested for the urethane oligomer (3a) formation (Table 1), starting from polyethylene glycol (PEG 400, 1a) and isophorone diisocyanate (IPDI, 2a).…”

“…TGA analysis of UV-cured films show two weight losses (Fig. 6) [5]. The first decomposition step occurs in the temperature range of 120 • C-350 • C and it is due to the thermal degradation of the hard segments, which involves the breakage of urethane linkage.…”

“…Green and sustainable catalytic reactions always find application in polymer synthesis, and particular attention is paid to 'precision polymerization' where the catalyst plays a key role [1]. In this context, rare earth-heterogeneous-catalyzed processes are widely applied to polymer synthesis [2], and cerium(III) salt based systems have found increasing application as eco-friendly catalysts for polymer synthesis innovation [3][4][5]. To our knowledge there are no data in the literature on the use of Ce(III) salts as catalysts in the preparation of polymers within the polyurethanes family.…”

The Influence of Metal Lithium and Alkyl Chain in the Nucleating Agent Lauroyloxy-Substituted Aryl Aluminum Phosphate on the Crystallization and Optical Properties for iPP

“…The structure of the nucleating agent APAl-12C is tested by FT-IR spectra in Figure 3a. The stretching vibration peaks of -CH 2 -and C=O are detected at about 2917 cm −1 and 1590 cm −1 , which are attributed to the characteristic peaks of lauroyloxy [25]. Moreover, a strong peak at approximately 1476 cm −1 could be assigned to the benzene ring stretching vibration [26].…”

Chemical, Thermal and Mechanical Characterization of Licorice Root, Willow, Holm Oak, and Palm Leaf Waste Incorporated into Maleated Polypropylene (MAPP)

“…In particular, holm oak has been considered as an alternative source for the production of cellulose pulp [ 11 ], willow flour has been proposed as filler for polyethylene matrix [ 12 ] and poly(lactic acid) into microcellular foam [ 13 ]. On the two remaining fillers, licorice root and palm oil waste, a study concerning their characterization before and after introduction in a limited amount into a poly(urethane-acrylate) (PUA) matrix has been carried out [ 14 ]. It is suggested that for all of the fillers considered, working with MAPP would enable their use as the matrix reinforcement in significant amounts, thus providing scope for further application.…”