A number of industrial and technical lignins from forestry and agriculture were extracted by different chemical pulping processes and characterized by evaluating their physical and chemical properties. Several qualitative and quantitative methods were performed to elucidate lignin profiles and their potentials as substitutes for use in biobased products. The morphology, molecular weight distributions, elemental compositions, glass transition temperature, and several important functional groups containing hydroxyl units such as phenolic, aliphatic, and carboxylic acid were classified and their contents were determined quantitatively by employing 31 P NMR spectroscopy. The emerging information is relevant to pressing scientific development issues for value-added applications from lignins during industrial production of biomaterials.
The effect of organo-nanoclay (Nanomer I30E) on the cure mechanism and kinetics of epoxy nanocomposites based on Epon 828 and Epicure 3046 was studied by means of dynamic differential scanning calorimetry (DSC) at four heating rates (2.5, 5, 10, and 20°C•min Ϫ1 ) and by Fourier transform infrared (FT-IR) spectroscopy. The DSC cure data for epoxy-amine mixtures with and without nanoclay was modeled by means of different approaches; the Kissinger and isoconversional models were used to calculate the kinetics parameters while the Avrami model was utilized to compare the cure behavior of the two systems. The Nanomer I30E was shown to initiate rapid homopolymerization of the Epon 828 resin at temperatures above 180°C. For the epoxy-amine mixtures, the presence of nanoclay had little effect on the cure kinetics in the early stages (i.e., at lower temperatures), and the apparent activation energy was around 60 kJ•mol Ϫ1 . However, in the later stages, the apparent activation energy increased significantly in the absence of nanoclay, but did not do so when it was present. The presence of nanoclay also lowered the final glass transition temperature by about 4°C.
Composite materials have played an important role throughout human history, from housing early civilizations to enabling future innovations. Composites offer many benefits; the key among them are corrosion resistance, design flexibility, durability, light weight, and strength. Composites have permeated our everyday lives such as products that are used in constructions, medical applications, oil and gas, transportation, sports, aerospace, and many more. Some applications, such as rocket ships, probably would not get off the ground without composite materials. This chapter addresses the advantages of fibre composite materials as well as fundamental effects, product development, and applications of fibre composites, including material chemistry, designing, manufacturing, properties, and utilisation of the materials in various applications.
A bio-based process for selective degradation of carbohydrate impurities from waste lignin was achieved using Pseudomonas fluorescens as a green cleaner.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.