Process for preparing polymers of p-xylylene from p-xylylene diesters

US5310858A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Andreas Greiner · Amöneburg, DE
• Peter Simon · Marburg, DE

Key dates

• Filing date: Jan 28, 1993
• Grant date: May 10, 1994
• Expiry date: Jan 28, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G61/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for preparing compounds of the formula (I) ##STR1## by pyrolysis, where n is the degree of polymerization and is.gtoreq.2. For this purposes compounds of the formula (II) EQU --R--CO--O--CH.sub.2 --Ar--CH.sub.2 --O--CO--R (II) are pyrolyzed in one stage under conditions resulting in cleavage of the ester bonds under a partial pressure of the esters of p.ltoreq.10 mbar at temperatures T.gtoreq.500.degree. C., with the formation of the corresponding derivatives of 1,4-dimethylene-2,5-cyclohexadiene, but without the latter being cleaved further in subsequent reactions. The polymers of p-xylylene formed by spontaneous polycondensation of the derivatives of 1,4-dimethylene-2,5-cyclohexadiene were then cooled, Ar and R have the following meanings: PA0 --Ar-- is a 1,4-phenylene radical or another C.sub.6 -C.sub.12 aromatic or heteroaromatic radical in which the bonds are in the para position or a comparable coaxial or antiparallel position; PA0 R-- is preferably branched or unbranched C.sub.1 -C.sub.4 -alkyl or C.sub.6 -C.sub.12 -aryl radical.