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Published in Joseph C. Salamone, Polymeric Materials Encyclopedia, 2020
D. K. Hoffman used liquid chromatography to investigate isocyanurate formation in model compound systems; the experiments were conducted in the absence of a solvent and used reactant concentrations similar to those found in the production of foams.26 An improved liquid chromatographic approach using diglyme (2-methoxyethyl ether), a polyether-like solvent, and an externally applied nonisothermal temperature profile was recently developed to determine changes in catalyst activity and selectivity during formation of the polyurethane.30 By using mixtures of phenyl and o-tolyl isocyanate, M. L. Listemann et al. were able to examine differences in catalytic activity in toluene diisocyanate (TDI) and 4,4′-diphenylmethane diisocyanate (MDI)-based formulations.30 Because of the physical and chemical simplifications (e.g., the presence of solvent and isothermal conditions) associated with most model compound studies, these experiments are best used to screen catalysts and generate relative rankings that may translate into performance in commercial polyurethanes.
Synthesis of Polythiophene-BasedArchitectural Macromolecules: RecentProgress in Controlled Polymerization
Published in Atsushi Nagai, Koji Takagi, Conjugated Objects, 2017
The chain-end-functional PTs are very important materials forpreparing BCPs, because the functional groups at the chain end(s)can be exploited for the introduction of the second block by the subsequent reactions or polymerizations. McCullough reportedthe preparation of a chain-end-functional P3HT by reacting P3HT-Ni(dppp)Br with a Grignard reagent (R-MgX) (see Scheme 6.7,termination method).69−71 The functional groups include methyl,butyl, ‘butyl, vinyl, allyl, phenyl, tolyl, benzyl, formyl (acetal protected),alcohol/phenol (tetrahydropyran protected), and 3-aminopropyl/p-aminophenyl (trimethylsilyl protected) (see Scheme 6.7).
Physical Properties of Individual Groundwater Chemicals
Published in John H. Montgomery, Thomas Roy Crompton, Environmental Chemicals Desk Reference, 2017
John H. Montgomery, Thomas Roy Crompton
Synonyms: AI3-00150; BRN 1305151; CCRIS 647; 4-Cresol; p-Cresol; p-Cresylic acid; EINECS 203-398-6; FEMA No. 2337; 1-Hydroxy-4-methylbenzene; p-Hydroxytoluene; 4-Hydroxytoluene; p-Kresol; 1-Methyl-4-hydroxybenzene; 4-Methylhydroxybenzene; p-Methylhydroxybenzene; p-Methylphenol; NSC 3696; 4-Oxytoluene; p-Oxytoluene; Paracresol; Paramethylphenol; RCRA waste number U052; 4-Toluol; p-Toluol; p-Tolyl alcohol; UN 2076.
Fluorinated Diluents- A Review
Published in Solvent Extraction and Ion Exchange, 2023
V. Babain, M. Alyapyshev, C. Ekberg, T. Todd
FS-13 was also used as diluent for DPA [54, 56]. The solubility of amides in both diluents (F3 and FS-13) is similar. A comparison of some fluorinated diluents for DPA was performed.[101] It was shown that the extraction ability of Am(III) and Eu(III) in all studied polar fluorinated diluents – F-3 and FS-13 is similar and higher than in chloroform. Later, most research with these compounds was done with F-3 or FS-13 as a diluent. The extraction of Am (III) and Eu(III) in different diluents was studied.[102] The extraction efficiency of N,N’-diethyl-N,N’-di(meta tolyl) DPA at 3 M HNO3 decreases in the following order: nitrobenzene > phenyltrifluoromethyl sulfone (FS-13) > 1,2-dichloroethane> lauryl nitrile > hexyl methyl ketone, (HMK, 2-octanone) > 1-octanol ∼ chloroform ∼ toluene ∼ isopropylbenzene.