An improved procedure for the methylation analysis of oligosaccharides and polysaccharides

Identification of organic compounds

Summary: Over the last several decades, the process of recycling polymer waste has been attracting the attention of many scientists working on this issue. Polymer recycling is very important for at least two main reasons: firstly, to reduce the ever increasing volumes of polymer waste coming from many sources: from daily life packaging materials and disposables and secondly, to generate value-added materials from low cost sources by converting them into valuable materials similar, to some extent, to virgin materials. Poly(ethylene terephthalate) (PET) occupies the top of the list of polymers to be recycled due to its easy recycling by different ways, which, in accordance, give variable products that can be introduced as starting ingredients for the synthesis of many other polymers. PET can by recycled by hydrolysis, acidolysis, alkalolysis, aminolysis, alcoholysis and glycolysis. Glycolysis is the breakdown of the ester linkages by a glycol, resulting in oligomers or oligoester diols/polyols with hydroxyl terminal groups. Oligoesters coming from the glycolysis of PET waste have been well known for a number of decades to be utilized as a starting material in the manufacture of polyurethanes, unsaturated polyesters and saturated polyester plasticizers. But, as a current motivation, we are reporting on a new application for these oligoester diols/polyols by converting the hydroxyl terminals into acrylate/methacrylate groups. These new acrylated/methacrylated oligoesters have been tested as UV curable monomers and gave promising results from the point of view of their curability by UV and their mechanical properties. The new motivations open the potential for the market to apply the depolymerization products of PET waste for UV curable coatings, useful for wood surfaces, paints and other applications.

Recycling of PET polymer by different chemical routes.

New motivation for the depolymerization products derived from poly(ethylene terephthalate) (PET) waste: a review

Separation and determination of nanogram amounts of inorganic tin and methyltin compounds in the environment

Introduction IN 1959 Norman et al1described a patient with a specific form of amaurotic idiocy which they called "Tay-Sachs Disease With Visceral Involvement." In this patient the clinical and pathological picture resembled Tay-Sachs disease, plus accumulation of lipid-laden histiocytes in liver, spleen, thymus, and other organs. Their patient's case differed chemically from Niemann-Pick disease, in which there is also combined neural and visceral involvement, in that the stored material in the brain was a ganglioside. In Niemann-Pick disease the characteristic lipid, which accumulates to a moderate degree in the brain and to a marked degree in the viscera, is sphingomyelin. Their patient's case also differed from classical Tay-Sachs disease since visceral involvement is absent in this disease. Also in 1959, Craig et al2described an infant with "foam-cell" histiocytosis of the viscera, involvement of renal glomerular epithelium, and clinical and radiological features suggestive of Hurler's disease. Since

J. S. Fritz

Papers

Acid-Catalyzed Acetylation of Organic Hydroxyl Groups