Formation of porous matrices from lactide and ε-caprolactone copolymers in supercritical carbon dioxide medium

A series of lactide and ε-caprolactone copolymers containing 4–24 mol % of ε-caprolactone with 20- to 30-kDa molecular weights are synthesized. Based on them, porous materials are produced by foaming in supercritical carbon dioxide. The pore size was shown to decrease with increasing ε-caprolactone content in copolymer, while the porosity of the entire sample was not altered. The resulting pore size also decreases if 7 wt % polyethylene glycol is added to the initial monomer mixture. The Young’s modulus of the porous samples decreases with increasing ε-caprolactone content and when polyethylene glycol is added.     

Existence of a differential realization of a dynamical system in a Banach space in the constructions of extensions to M p -operators

For families of continuous controlled dynamic input-output processes, we obtain and discuss necessary and sufficient conditions for their differential realization in the class of quasilinear nonstationary differential equations of state in a Banach space.     

Synthesis of a New Benzoate Plasticizer for Polyvinyl Chloride Based on a 2-Ethylhexanol By-Product

Russian Journal of Applied Chemistry - When 2-ethylhexyl alcohol is produced by the propylene oxo synthesis, 2-ethylhexanol distillation residue (EDR), a large-tonnage by-product, is formed....     

Sulfonium ylides

The intramolecular cyclization of keto-stabilized sulfonium ylides obtained from β-alanine and containing various imide fragments was studied. On heating in toluene in the presence of PhCO₂H, ylides containing a phthalimide moiety are converted into indolizidine-2,6-dione derivatives, whereas those incorporating a 4-methyl-1,2,3,6-tetrahydrophthalimide or pyrrolidine-2,5-dione moieties do not undergo cyclization. For Part 6, see Ref. 1 Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2008–2012, November, 1997.     

Sulfur ylides. 12. Optically active keto stabilized sulfur ylide obtained from L-proline: synthesis and study

Optically active keto stabilized sulfur ylide was synthesized from L-proline. The reactions of the ylide with methyl acrylate and methyl vinyl ketone afforded 1,2-disubstituted cyclopropanes. In the case of acrylonitrile, a mixture of 1,2- and 1,1-disubstituted cyclopropanes was obtained. Acylation of the ylide with acetic anhydride gave twice stabilized sulfur ylide.     

Ester plasticizers for polyvinyl chloride

The review covers information from patents and papers that have been published in the past 5 years and deal with the synthesis of ester plasticizers for polyvinyl chloride. The main trends in the progress of this field are analyzed. Data on new esterification catalysts are presented. Particular attention is paid to plasticizers derived from terephthalic acid, which show promise for replacing toxic dioctyl phthalate. The results of studies on synthesis and properties of nonphthalate plasticizers based on benzene, toluene, naphthalene, cyclohexane, and norbornene are considered. Synthesis methods and prospects for using plasticizers derived from renewable vegetable raw materials, namely, citrates, succinates, triglycerides, fatty acid esters, and sugar derivatives, are discussed.