RESUMEN
The packaging industry has primarily been dominated by single-use, petrochemical-sourced plastic materials despite their short-term use. Their leakage into the ecosystem after their use poses substantial environmental concerns. As a result, compostable and renewable packaging material alternatives are garnering significant attention. Cellulose acetate is a derivative of cellulose that exhibits excellent tensile properties, transparency, melt processability, and intermediate compostability. However, its application in the food packaging industry is limited due to its hygroscopic behavior and lack of dimensional stability. This study investigated using lignin (pristine and esterified) as a functional additive of cellulose acetate. The effect of varying concentrations of pristine kraft and oleic acid functionalized lignin in the cellulose acetate matrix and its effect on the resulting film's mechanical, morphological, viscoelastic, and water barrier properties were explored. Comprehensive characterization of the thermomechanical processed lignin-cellulose acetate sheets revealed reduced moisture absorption, improved UV and moisture barrier, and enhanced tensile properties with melt processability. Overall, the studied films could have appealing properties for food and other packaging applications, thus, serving as eco-friendly and sustainable alternatives to conventional petroleum-derived packing materials.
Asunto(s)
Celulosa , Interacciones Hidrofóbicas e Hidrofílicas , Lignina , Ácido Oléico , Resistencia a la Tracción , Lignina/química , Lignina/análogos & derivados , Celulosa/química , Celulosa/análogos & derivados , Ácido Oléico/química , Embalaje de Alimentos/métodos , Agua/químicaRESUMEN
Pickering emulsions offer numerous advantages over conventional surfactant-stabilized emulsion systems, including lower loading levels and enhanced long-term stability. Through both organic and inorganic Pickering emulsifying particles exist, more efforts are being invested in devising renewable, biodegradable, and non-toxic alternatives to conventional Pickering emulsifiers. In this study, the use of lignin (unmodified and esterified) specimens as an effective alternative to conventional Pickering emulsifiers was investigated. Hexanoyl chloride, decanoyl chloride, and palmitoyl chloride esterified lignin specimens were produced and their employability as Pickering emulsifiers was studied. The effects of varying the concentrations of lignin (unmodified and esterified specimens) and pH of the dispersion medium on the stability of the produced Pickering emulsions were explored. Comprehensive characterization of the esterified lignin stabilized Pickering emulsions exhibited enhanced stability, and smaller average oil droplet size, resulting in stable Pickering emulsions with high zeta potential and better flow properties. Overall, the studied esterified lignin specimens can have appealing applications in various Pickering emulsion systems, as a nontoxic and sustainable alternative to conventional emulsifiers.
Asunto(s)
Cloruros , Lignina , Emulsiones/química , Esterificación , Emulsionantes/química , Ácidos Grasos , Agua/química , Tamaño de la PartículaRESUMEN
Sustainable and biodegradable packaging materials are appealing alternatives to the petrochemical-derived and non-biodegradable plastics that currently dominate the market. However, their inferior barrier properties and high cost inhibit their widespread applications. In this work, pristine and esterified lignin were investigated as a functional filler of poly (butylene adipate-co-terephthalate) (PBAT) based bioplastic paper coating formulations. For this, the pristine and esterified lignin (10-50 wt%) were separately dispersed in a solvent and incorporated in PBAT solutions and applied on paper substrates. The effects of varying concentrations of pristine and esterified lignin on the rheology, mechanical, morphology, and barrier properties of the coated paper substrate were investigated. Comprehensive characterization of esterified lignin/PBAT coatings exhibited enhanced dispersion of the lignin fraction in the PBAT, resulting in excellent wet tensile properties and enhanced water, oil, and oxygen barrier performance. Overall, the studied coating formulations have appealing properties for food contact materials, such as paper wraps and paperboard applications, as a sustainable and eco-friendly alternative to the incumbent coating materials, such as petroleum sourced waxes and polyolefin-based coatings.