关键词: intermolecular transalkylation;diisopropylnaphthalene;polyisopropylnaphthalene; monoisopropyl-naphthalene;2;6-diisopropylnaphthalene;amorphous silica-alumina

Abstract: Isopropylation of naphthalene with propene resulted in a variety of isomers having
different alkylation levels. The most important isomer is 2,6-DIPN, which is the precursor
of important monomer 2,6-naphthalene di-carboxylic acid used for making liquid crystal
polymers. In order to increase the yield of 2,6-DIPN, the intermo-lecular transalkylation
with naphthalene was applied to the mixture of other DIPNs and PIPN to obtain MIPN en-
riched product, which underwent isopropylation with propene to produce 2,6-DIPN in a higher
yield. The experi-mental study showed that the preferable conditions for transalkylation
were reaction temperature of 325℃, the mo-lar ratio of isopropyl group to naphthyl group
(IP/N) of 0.8︰1—0.9︰1, reaction time of 4h and 5% of amorphous silica-alumina by mass.
The conversions of DIPN and PIPN in its mixture were 62%—69% and 87%—88% respec-tively
and the yield of MIPN was greater than 40%. The mixture of MIPN enriched product and
recovered MIPN from rectification was subject to isopropylation with propene at 275℃ over
a shape-selective catalyst to produce 2,6-DIPN in a yield up to 38%. A recycled process of
recovered components was established, through one cycle the yield of 2,6-DIPN based on
naphthalene may be 2.8 times higher than before, and the utilization ratio of raw naph-
thalene was increased by 46%.

Key words: intermolecular transalkylation, diisopropylnaphthalene, polyisopropylnaphthalene, monoisopropyl-naphthalene, 2, 6-diisopropylnaphthalene