RESUMO
In the last decades, metallopolymers have received great attention due to their various applications in the fields of materials and chemistry. In this article, a neutral 18-electron exo-substituted η(4) -cyclopentadiene CpCo(I) unit-containing polymer is prepared in a controlled/"living" fashion by combining facile click chemistry and ring-opening meta-thesis polymerization (ROMP). This Co(I)-containing polymer is further used as a heterogeneous macromolecular catalyst for atom transfer radical polymerization (ATRP) of methyl methacrylate and styrene.
Assuntos
Cobalto/química , Substâncias Macromoleculares/química , Polimerização , Polímeros/química , Catálise , Substâncias Macromoleculares/síntese química , Espectroscopia de Ressonância Magnética , Modelos Químicos , Estrutura Molecular , Polímeros/síntese químicaRESUMO
The development of sustainable renewable polymers from natural resources has increasingly gained attention from scientists, engineers as well as the general public and government agencies. This review covers recent progress in the field of renewable bio-based monomers and polymers from natural resources: terpenes, terpenoids, and rosin, which are a class of hydrocarbon-rich biomass with abundance and low cost, holding much potential for utilization as organic feedstocks for green plastics and composites. This review details polymerization and copolymerization of terpenes such as pinene, limonene, and myrcene and their derivatives, terpenoids including carvone and menthol, and rosin-derived monomers. The future direction on the utilization of these natural resources is discussed.
Assuntos
Polímeros/química , Resinas Vegetais/química , Terpenos/química , Biomassa , Química Click , Química Verde , Polimerização , Polímeros/síntese química , Resinas Vegetais/síntese química , Terpenos/síntese químicaRESUMO
Stormwater runoff in a rapidly urbanizing region was analyzed for organic contamination to compare impervious and pervious surfaces. Total petroleum hydrocarbons (TPH) ranged between 5 and 277 mg/L, with impervious surfaces showing, on average, greater TPH concentrations. Pyrene and fluoranthene were identified in all impervious stormwater samples. Sediments from receiving waters also contained pyrene and fluoranthene. Runoff samples had concentrations in the range of 11-191 microg/L. Sediment samples ranged from 2.3 x 10(1)-1.3 x 10(4) microg/kg. Results from this study are useful for identifying major urban contaminants and understanding the role of pervious surfaces in filtering urban contaminants.
Assuntos
Fluorenos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos/análise , Chuva , Urbanização , Movimentos da Água , Poluentes Químicos da Água/análise , Adsorção , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Sedimentos Geológicos/análise , Sedimentos Geológicos/química , Oxigênio/química , Oxigênio/metabolismo , TemperaturaRESUMO
Multifunctional abietane-based polymer nanogels were fabricated for label-free cell imaging and drug delivery. The self-fluorescent abietane as the framework of carriers enables the imaging without the need for external fluorescent probes, while abietane-based nanogels exhibit low in vitro cytotoxicity.
Assuntos
Portadores de Fármacos/química , Polietilenoglicóis/química , Polietilenoimina/química , Polímeros/química , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/toxicidade , Corantes Fluorescentes/química , Humanos , Células MCF-7 , Microscopia Confocal , NanogéisRESUMO
We report novel robust resin acid-derived antimicrobial agents that exhibit excellent antimicrobial activities against a broad spectrum of bacteria (6 Gram-positive and 7 Gram-negative) with selective lysis of microbial membranes over mammalian membranes. Our results indicate that hydrophobicity and unique structures of resin acids can be determining factors in dictating the antimicrobial activity.