The polymerization of isobutylene allows us to obtain a wide spectrum of polyisobutylenes (PIBs) which differ in their molecular weight characteristics and the chemical structure of chain-end groups. The bulk of the PIBs manufactured worldwide are highly reactive polyisobutylenes (HRPIBs) with -C(Me)=CH end-groups and low-molecular weights ( < 5 kDa). HRPIBs are feedstocks that are in high demand in the manufacturing of additives for fuels and oils, adhesives, detergents, and other fine chemicals. In addition, HRPIBs and CMeCl-terminated PIBs are intensively studied with the aim of finding biomedical applications and for the purpose of developing new materials. Both chain control (molecular weight and dispersity) and chemoselectivity (formation of -olefinic or -CMeCl groups) should be achieved during polymerization. This review highlights the fundamental issues in the mechanisms of isobutylene polymerization and PIB analysis, examines actual catalytic approaches to PIBs, and describes recent studies on the functionalization and applications of HRPIBs and halogen-terminated PIBs.
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http://dx.doi.org/10.3390/polym15163415 | DOI Listing |
Environ Sci Technol
January 2025
Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec H4B 1R6, Canada.
Coal tar-related products as a source of polycyclic aromatic compounds (PACs) are particularly concerning due to high PAC concentrations and inadequate source management. Benzo[b]carbazole, a benzocarbazole isomer exclusively found in coal tar-derived products, acts as an ideal marker to distinguish coal tar sources from others, enabling more robust quantification of coal tar contributions to PACs. To evaluate the historical and recent contributions of coal tar-related sources to the levels of PACs in Lake Ontario and associated ecological risk, we analyzed 31 PACs and 3 BCBz isomers in surface sediments and a sediment core.
View Article and Find Full Text PDFBiochimie
January 2025
Jagiellonian University Medical College, Faculty of Health Sciences, Department of Medical Physiology, Chair of Biomedical Sciences, 12 Michalowskiego st., 33-332 Cracow, Poland.
Obesity treatment requires an individualized approach, emphasizing the need to identify metabolic pathways of diagnostic relevance. Toll-like receptors (TLRs), particularly TLR2 and TLR4, play a crucial role in metabolic disorders, as receptor deficiencies improves insulin sensitivity and reduces obesity-related inflammation. Additionally, hydrogen sulfide (HS) influences lipolysis, adipogenesis, and adipose tissue browning through persulfidation.
View Article and Find Full Text PDFToxicology
January 2025
National Institute of Health Doutor Ricardo Jorge, I.P (INSA), Department of Human Genetics, Lisbon, Portugal; (b)Centre for Toxicogenomics and Human Health (ToxOmics), NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal. Electronic address:
Understanding the potential impact of nanomaterials (NMs) on human health requires further investigation into the organ-specific nano-bio interplay at the cellular and molecular levels. We showed increased chromosomal damage in intestinal cells exposed to some of in vitro digested Titanium dioxide (TiO) NMs. The present study aimed to explore possible mechanisms linked to the uptake, epithelial barrier integrity, cellular trafficking, as well as activation of pro-inflammatory pathways, after exposure to three TiO-NMs (NM-102, NM-103, and NM-105).
View Article and Find Full Text PDFJ Genet Genomics
January 2025
State Key Laboratory of Maize Bio-breeding, Key Laboratory of Genome Editing Research and Application, Ministry of Agriculture and Rural Affairs, Department of Plant Genetics and Breeding, National Maize Improvement Center, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China; Frontiers Science Center for Molecular Design Breeding, Beijing 100193, China. Electronic address:
Transcription factors play critical roles in the regulation of gene expression during maize kernel development. The maize endosperm is a large storage organ, accounting for nearly 90% of the dry weight of mature kernel, and is also the main place for starch storage. In this study, we identify an endosperm-specific EREB gene, ZmEREB167, which encodes a nucleus-localized EREB protein.
View Article and Find Full Text PDFWater Res
January 2025
College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, PR China; Key Laboratory of Arable Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225127, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225127, Jiangsu, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, PR China. Electronic address:
Endogenous nitrogen (N) release from lake sediments is one of main causes affecting water quality, which can be affected by the presence of iron (Fe) minerals and organic matter, especially low-molecular-weight organic acids (LMWOAs). Although these substances always coexist in sediments, their interaction effect on N fate is not yet clear. In this study, the role and mechanisms of the coexistence of iron mineral (ferrihydrite, Fh) and LMWOAs, i.
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