Simple and Precision Approach to Polythioimidocarbonates and Hybrid Block Copolymer Derivatives was written by Lai, Tao;Zhang, Pengfei;Zhao, Junpeng;Zhang, Guangzhao. And the article was included in Macromolecules (Washington, DC, United States) in 2021.Application of 2253-73-8 The following contents are mentioned in the article:
The advancement of polymeric materials relies heavily on the innovation in polymerization reactions. In this study, we have discovered alternating copolymerization of isothiocyanate (ITC) and epoxide, which results in a nearly unexploited sulfur-containing polymer, polythioimidocarbonate (PTC). Provided with a simple two-component catalyst, i.e., a Lewis pair consisting of triethylborane (Et3B) and excess phosphazene base (PB), the copolymerization starts from an alc. and proceeds in a strictly alternating and highly chemoselective manner, yielding PTC with controlled molar mass and low dispersity, free of cyclic byproducts and ether linkages. The method applies well to a variety of ITCs and epoxides. It is also found with great excitement that the reaction on ITC is fully inhibited when the catalyst composition is inverted to have Et3B in excess, while homopolymerization of epoxide occurs selectively in this case. D. functional theory (DFT) calculation reveals that Et3B-alkoxide complexation is the key to suppressing the back-biting reaction during the copolymerization ([Et3B] < [PB]) and inhibiting the copolymerization ([Et3B] > [PB]). This unique “biased” feature is harnessed to develop a catalyst switch strategy for one-pot block copolymerization from the mixture of ITC and epoxide following either a copolymerization or homopolymerization of the first order, resulting in tailor-made PTC-polyether block copolymers with reversible sequence structures. On the other hand, sequence-selective terpolymn. occurs from a mixture of phthalic anhydride, ITC, and epoxide, allowing the one-step synthesis of polyester-PTC block terpolymer. These results have highlighted the versatility of the method for exploring this uncharted area of polymers. This study involved multiple reactions and reactants, such as Isopropylisothiocyanate (cas: 2253-73-8Application of 2253-73-8).
Isopropylisothiocyanate (cas: 2253-73-8) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Application of 2253-73-8
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics