Drying of softwood kraft lignin and its cationic derivatives

Abstract

Our dependence on petroleum-based materials comes with significant environmental challenges such as environmental pollution, including oil spills and air pollution. Furthermore, the utilization of petroleum-based products leads to the emission of greenhouse gases, which contributes to climate change. Additionally, many petroleum-based products, such as plastics, are not biodegradable and accumulate in the environment, causing harm to wildlife and ecosystems. For these reasons, researchers continue to seek out sustainable alternatives to petroleum-based materials. Lignin is a promising starting material for producing sustainable and environmentally compatible chemistries. Lignin is an abundant and sustainable resource. Organic synthesis and polymerization reactions are utilized as effective methods for derivatizing lignin and tailoring it for application in various industries. After synthesis and purification, drying is a crucial final step. Generally drying conditions should be carefully selected to introduce minimal changes to the properties of the synthesized products. Furthermore, there have been reports of lignin’s sensitivity to heat, stimulating condensation reactions which alter the properties of the sample. There are no comprehensive studies that investigate the topic of drying of lignin derivatives. In this work, the objectives were to derivatize lignin in two ways via: 1) grafting reaction to create a low molecular weight cationic lignin derivative and 2) polymerization to create a high molecular weight cationic lignin derivative. [...]