Elaboration, characterization, and degradation of composite material: Lignocellulosic/unsaturated polyester

Abstract

The present work deals with the valorization of the lignin. The lignin is a by-product of the black liquor of the paper industry, which has a very complex composition structure. In this study, this lignin is obtained from the Alfa grass (Stipa Tenacissima L, also named Esparto grass). A composite material with polymer matrix (unsaturated polyester) reinforced with the lignin at various proportions has been elaborated and a comparison of its mechanical and physico-chemical characteristics to another type of composite material constituted of polymer matrix (unsaturated polyester) reinforced with Alfa fibers has been achieved. The characterization of these composites materials is based on tensile as well as thermal degradation tests under isothermal conditions. In order to explain the deviation from the linear profile (weight losses), a mathematical model has been used to show that the degradation energy is the same for all temperature ranges. This model allowed us to calculate the activation energy (48 kJ/mole.K), which corresponds to the process of off-gassing, break of macromolecular chains and weight loss.

Alternatives for Chemical and Biochemical Lignin Valorization: Hot Topics from a Bibliometric Analysis of the Research Published During the 2000–2016 Period

“…Several studies have investigated the modification of the properties due to the presence of lignin in the structure [452]. Polyester resins with lignin replacing the traditional polyols have been produced and the resulted material exhibited mechanical and thermal resistance properties no lower than the traditional formulations [453]. Moreover, lignin-polyester copolymers with elastomeric properties have been developed.…”

Study of the tensile and compression performance of composite materials based on rubber particles and alpha fibers

“…Like similar lignocellulosic fibers (agave, sisal, palm fiber, etc. ), Alfa fibres can be used in various fields [30].…”

“…The Alfa grass fiber (Stipa Tenacissima L, also named Esparto grass) is a common vegetable fiber and its use is widespread [15,24,27,30]. We usually use it as a plant or as short fibers.…”

“…Therefore, different morphological structures of Alfa fibers were chemically and mechanically modified to be widely used on polymer matrixes [2,12–14,18,22,25–29]. Alfa stems, Alfa ( Stipa tenacissima ), cyanoethylated Alfa fibers, and long Alfa fibers, extracted from the stem of the Alfa, were used to prepare composite materials [9,15,19,20,22,30].…”

“…Both the crystallinity index and thermal stability of treated Alfa fibers were discussed [26]. Alfa stems were treated with NaOH solution with two different concentrations [30]. Comparison and analysis of results confirmed some thermal, structural, and morphological changes of the fibers after treatment due to the removal of some non-crystalline constituents from the plant [26].…”