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Organic Chemicals
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
The reactions of amines and phosgene give isocyanates and carbamate esters. Isocyanates are of great importance for making polyurethanes. Polyurethanes are polyaddition products formed from diisocyanates and dehydric alcohols or diamines. Polyurethane is a textile raw material for elastomers, for example, rubber-elastic continuous-filament yarns, and starting materials for foam plastics.
Polymer drug conjugates containing memantine, tacrine and cinnamic acid: promising nanotherapeutics for the treatment of Alzheimer’s disease
Published in Journal of Microencapsulation, 2023
Tobeka Naki, William Morwa Reagile Matshe, Mohammed Olusegun Balogun, Suprakas Sinha Ray, Samuel Ayodele Egieyeh, Blessing Atim Aderibigbe
Michael addition polymerisation is a flexible synthetic approach useful for generating polymers ranging from linear to hyperbranched polymers (Sun et al. 2017). Aqueous Michael’s addition polymerisation technique was used to synthesise the polymer-drug conjugates in this study. The conjugates are prepared in water in a one-pot process and are characterised by linear architectures. The reaction involves a nucleophilic addition of a nucleophile to an α, β-unsaturated carbonyl compound. Under mild reaction conditions, the reaction is useful for forming C–C bonds. The advantages of Michael addition reactions are high conversions, the capability to accommodate high functional groups and favourable reaction rates (Aderibigbe et al. 2020). The aza Michael polyaddition of prim-monoamines or bis-sec-amines with bis-acrylamides yields a synthetic polymer called linear polyamidoamines (PAAs) (Marcioni et al. 2021). PAAs are polymeric carriers with high structural flexibility. They can be engineered to be biodegradable and biocompatible, and are mostly highly water-soluble and hydrophilic. Their capability to hydrolytically degrade in aqueous systems arise from the amide bond on their backbone. Most of them have demonstrated promising antiviral activity, useful as sensor constituents, heparin complexing agents, heavy metal ion complexing agents, transfection promoters and drug delivery systems (Coué and Engbersen 2011, Marcioni et al. 2021). Polymer-drug conjugates are nanoscale systems in which a drug molecule is covalently attached to a polymer backbone (Duro-Castano et al.2015).
Combining a bio-based polymer and a natural antifoulant into an eco-friendly antifouling coating
Published in Biofouling, 2020
Ho Yin Chiang, Jiansen Pan, Chunfeng Ma, Pei-Yuan Qian
PLA-PU was synthesized by polyaddition (Scheme 1). For the synthesis, 3.72g (16.7mmol) of IPDI and 5.00g (2.5mmol) of PLA diol were introduced to a round-bottom flask equipped with a condenser under nitrogen atmosphere with THF as the solvent. The mixture was stirred at 70°C for 1h yielding a prepolymer. Then 1.28g (14.2mmol) of BDO and 0.02g (0.2wt% based on monomers) of DBTDL were added as the chain extender and catalyst respectively, and the mixture was allowed to react at 80°C for 3h. The resulting polymer was precipitated in excess hexane twice, filtered and dried under vacuum at 60°C for 24h. Information on 1H NMR (600MHz, CDCl3, ppm): 5.16 (HNCOOCH(CH3)COO), 1.57 (HNCOOCH(CH3)COO), 4.07 (OCH2CH2CH2CH2O), 1.69 (OCH2CH2CH2CH2O), 3.79 (CH2CH(CH2)NHCOO), 2.91 (OOCNHCH2C(CH2)2CH3). 1H NMR and IR spectra is provided as supplementary materials.
Anti-biofilm effect of a butenolide/polymer coating and metatranscriptomic analyses
Published in Biofouling, 2018
Wei Ding, Chunfeng Ma, Weipeng Zhang, Hoyin Chiang, Chunkit Tam, Ying Xu, Guangzhao Zhang, Pei-Yuan Qian
Butenolide was synthesized by Shanghai Medicilon Inc. (Shanghai, China). The structure is shown in Figure 1. DCOIT was obtained from The Dow Chemical Company (Midland, MI, USA). The molar masses and dispersity of the poly (ε-caprolactone)-based polyurethane used in the present study were 27,000 and 1.87, respectively. Poly (ε-caprolactone)-based polyurethane was prepared by polyaddition according to the steps described in a previous study (Ma et al. 2013), and a general experimental procedure was as follows: first, isophorone diisocyanate was allowed to react with poly (ε-caprolactone) diol at 70°C for 1 h in tetrahydrofuran under a nitrogen atmosphere, yielding a prepolymer. Subsequently, 1,4-butanediol and dibutyltin dilaurate (DBTDL) were added as the chain extender and catalyst, respectively, and the mixture was allowed to react at 80°C for 3 h. The product was precipitated into hexane twice, filtered, and dried under vacuum at 40°C for 24 h.