Compatibility Estimation of Oligobutadienediol with Simple Oligoetherpolyols for Molded Polyurethane Compositions Development
This article includes the results of compatibility of oligomeric hydroxyl-containing butadienerubber with oligoetherpolyols on the basis of propylene oxide (Laprols). The compatibility limits of liquid hydroxyl-containing butadiene rubber of Krasol LBH-3000V brand with polypropyleneglycols of Laprol brand with different molecular weights were determined.
Oligomers Solidification Depending on the Nature, Molecular Mass, Type and Reactional Group Containing
The article is devoted to regularity defining of curing oligomers, and prepolymers with hydroxyl and isocyanate groups and double bonds reactive oligomers. The features of the spatial structure of elastic polyurethane based oligomers and prepolymers with the definition of the physical and chemical bonds share, as well as the chain interval length between grid points were researched. The possibility of oligodiendiole curing in the presence of a methacrylate component on the mechanism of radical polymerization was experimentally confirmed. To achieve the objectives rheokinetic method of analysis (rotational viscometer), thermometric and iodometric methods, IR spectroscopy, differential scanning calorimetry were used.
Practical, legal, and ethical issues in expanded access to investigational drugs.
The authors review the FDA policies and procedures that permit some patients with serious conditions to receive investigational drugs before formal product approval and examine the legal and ethical issues associated with expanded access.