Etherification of glycerol with tert-butyl alcohol catalysed by ion-exchange resins

Abstract

The reaction of glycerol with tert-butyl alcohol in the liquid phase on acid Amberlyst-type ion-exchange resins was studied. The influence of temperature, mole ratio n(TBA)/n(G), water and swelling of gel, and macroreticular type of polymer catalysts on etherification reaction was investigated. The most favourable reaction temperature is 75°C. The conversion of glycerol and yield of glycerol tert-butyl ethers has increased with the mole ratio n(TBA)/n(G). Dry form of macroreticular catalysts provided the best results. Etherification reaction of glycerol with isobutylene in non-aqueous conditions gives the highest yield of desired ethers. The influence of water was studied. The gel forms of ion-exchange resins have very low catalytic activity. It can be concluded that water has an inhibition effect on ion-exchange resins. By comparing the gel and macroreticular forms of Amberlyst ion-exchange resins it can be concluded that very acid forms of macroreticular ion-exchange resins with a high degree of crosslinking are more active catalysts for the studied reaction due to their pores which are sufficiently large so that the voluminous tert-butyl ethers of glycerol can be formed. It was estimated that tert-butyl alcohol as tert-butylation agent is not suitable for etherification of glycerol with the formation of di-and triethers.

Influência da temperatura e da natureza do catalisador na polimerização do glicerol

“…Vários trabalhos [27,[29][30][31][32][33][34][35][36] descrevem a polimerização do glicerol para obter oligômeros (Figura 2), (1 ≤ n ≤ 18), utilizando catalisadores homogêneos e heterogêneos. Nesses trabalhos, são apresentadas moléculas de cadeia curta e simples (di, tri, tetra, penta e hexaglicerol) como produto.…”

Qualitative and Quantitative Chromatographic Methods for Analysis of Glyceroltert-Butylation Reaction Product

“…A terc-butilação da glicerina 1 consiste em um conjunto complexo de reações consecutivas reversíveis, catalisadas por ácido, com a formação de mono-tercbutilgliceróis (MTBG), di-terc-butilgliceróis (DTBG) e tri-terc-butilglicerol (TTBG), conforme Figura 1.…”

Purification of glycerol/water solutions from biodiesel synthesis by ion exchange: sodium and chloride removal. Part II

“…13 -16 In almost all the applications of ion exchangers as catalyst in organic synthesis a macroporous resin has been employed. 17,18 Although our research group has made efforts to study the behavior of a gelform resin in the removal of alkaline metal ions from non-aqueous mixtures, experimental data on the performance of such resins in non-aqueous media are scarce. 19 -21 If the studies and practical applications of ion exchange for the purification of non-aqueous solution are scant, the knowledge of the influence of the proportions of different solvents in a mixture or the polarity of the solvents on the ion exchange equilibrium or kinetic are almost non-existent.…”