AppliedChem, Volume 5, Issue 1 (March 2025) – 3 articles

Lignin, a renewable and widely available biopolymer, has been explored as an additive in polyolefins to develop high value-added materials. However, its low compatibility with polymers like polypropylene (PP) often causes poor particle dispersion and compromised mechanical properties. Esterification has proven effective in enhancing lignin-polyolefin interactions. This study evaluated the incorporation of kraft lignin (KL) and maleic anhydride-modified kraft lignin (MAKL) into PP, focusing on lignin dispersion and the blends’ thermal, mechanical, and viscoelastic properties. Thermal analyses showed that MAKL reduced PP crystallinity, indicating improved compatibility, supported by micrographs showing more uniform particle dispersion. Mechanically, low MAKL concentrations maintained yield strength similar to neat PP, while 5 wt% MAKL increased impact strength by up to 148%. This improvement was attributed to enhanced interfacial interaction, reduced crystallinity, and better energy dissipation. The findings demonstrate that esterification of lignin with maleic anhydride effectively overcomes compatibility limitations with PP, leading to significant gains in mechanical and viscoelastic properties. This work advances lignin’s sustainable use in polymer blends, emphasizing its potential as a renewable alternative in material development. Full article

The annually wasted amount of food has surpassed 1 billion metric tons. Food waste is considered as an important source for the recovery of bioactive compounds, such as carotenoids. There is a demand for antioxidants, nutraceuticals and natural colorants in various industries and carotenoids are one of the commonly used compounds that fit this description. Pumpkin and spinach waste, whose combined amount is over 2 million metric tons, contains bioactive compounds and these wasted foods could be utilized for the recovery of carotenoids. Carotenoids are hydrophobic molecules; therefore, commercial extraction processes often use highly non-polar solvents, and these are rarely environmentally friendly. The aim of this research was to develop effective extraction processes for carotenoids from pumpkin and spinach using environmentally friendly green chemicals. A series of deep eutectic solvents (DESs) composed with L-menthol and carboxylic aliphatic acids were made for the extraction of carotenoids from pumpkin (Cucurbita moschata) and spinach (Spinacia oleracea) via mechanical mixing–assisted extraction (MMAE) and homogenization-assisted extraction (HAE). Response surface methodology (RSM) and analysis of variance (ANOVA) were used to analyze the data and optimization. The DESs composed from L-menthol and propionic acid had the best effect on the extraction of total carotenoid content (TCC) (represented as β-carotene) from pumpkin and spinach via solutions with 1:2 and 1:4 molar ratios, respectively. The yield of carotenoid extraction is expressed in μg-β-carotene/g of pumpkin or spinach. Under the calculated optimum conditions, the yields are estimated to be 11.528 μg-β-carotene/g-pumpkin for the MMAE method, 8.966 μg-β-carotene/g-pumpkin for the HAE method, 16.924 μg-β-carotene/g-spinach for the MMAE method and 18.870 μg-β-carotene/g-spinach for the HAE method. Full article

As the demand for environmentally friendly materials continues to rise, poly(lactic acid) (PLA) has emerged as a promising alternative to traditional plastics. The present review offers a comprehensive analysis of the biodegradation behavior of PLA in diverse environmental settings, with a specific focus on soil, compost, water, and wastewater environments. The review presents an in-depth comparison of the degradation pathways and kinetics of PLA from 1990 to 2024. As the presence of different microorganisms in diverse environments can affect the mechanism and rate of biodegradation, it should be considered with comprehensive comparisons. It is shown that the mechanism of PLA biodegradation in soil and compost is that of enzymatic degradation, while the dominant mechanisms of degradation in water and wastewater are hydrolysis and biofilm formation, respectively. PLA reveals a sequence of biodegradation rates, with compost showing the fastest degradation, followed by soil, wastewater, accelerated landfill environments, and water environments, in descending order. In addition, mathematical models of PLA degradation were reviewed here. Ultimately, the review contributes to a broader understanding of the ecological impact of PLA, facilitating informed decision-making toward a more sustainable future. Full article