Fractional precipitation of sodium polyphosphate and characterization by 31P NMR: an experiment for pysical chemistry classes

Quimica nova

Galembeck, Fernando¹  Damasceno, Fernando Cruvinel²  Alcantara, Glaucia Braz²  Lima, Emília Celma de Oliveira²  Moita Neto, José Machado³ 

[1] Universidade Estadual de Campinas, Campinas, Brasil;Universidade Federal de Goiás, Goiânia, Brasil;Universidade Federal do Piauí, Teresina, Brasil

关键词: sodium polyphosphate;    fractional precipitation;    31P NMR.;   

DOI  :  10.1590/S0100-40422010000900031

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

This text describesan experiment on fractional precipitation of a polymer together with determinationof average degree of polymerization by NMR. Commercial sodium polyphosphatewas fractionated by precipitation from aqueous solution by adding increasingamounts of acetone. The polydisperse salt and nine fractions obtained from itwere analyzed by 31P Nuclear Magnetic Resonance and the degree ofpolymerization of the salts and of the fractions were calculated. Long-chainsodium polyphosphate was also synthesized and analyzed. This experiment wastested in a PChem lab course but it can be used also to illustrate topics ofinorganic polymers and analytical chemistry.

【 授权许可】

CC BY