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Purification of 2,6‐Diisopropylnaphthalene by Static Melt Crystallization from a Mixture Containing Diisopropylnaphthalene Isomers
Author(s) -
Tian ZhengHua,
Jia HongMin,
Zhao GuiLi,
Hu WeiQi
Publication year - 2007
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200790002
Subject(s) - chemistry , crystallization , yield (engineering) , naphthalene , solvent , phase diagram , boiling point , monomer , propene , phase (matter) , alkylation , thermodynamics , organic chemistry , catalysis , physics , polymer
2,6‐Diisopropylnaphthalene (2,6‐DIPN), as the precursor of important monomer 2,6‐naphthalene dicarboxylic acid, could be produced by the shape‐selective isopropylation of naphthalene with propene resulting in an isomeric mixture having different alkylation levels. Since the boiling points of DIPNs were very close and the differences of melting points in‐between isomers were quite distinctive, the static melt crystallization was applied to separate and purify 2,6‐DIPN from its isomers. 2,6‐DIPN with purity ≥99% was produced through a process of three stages: crystallization→sweating→melting. The phase diagram of 2,6‐DIPN‐2,7‐DIPN binary system was plotted to optimize the temperature control of crystallization. By repeated crystallization of melts with different concentration levels, the yield of pure 2,6‐DIPN could be enhanced to 87%. No solvent was necessary.