Appeal No. 1996-1529
Application No. 08/233,219
residues. The hydroxyl groups at the end of the polymer chain attack other activated cyclic ether
monomers, opening the rings and again leaving terminal hydroxyl groups. Polymerization proceeds until
the cyclic ether monomers are substantially exhausted or the reaction is terminated by other means.
The acid catalyst may be a Lewis acid and the alcohol may be mono- or difunctional. (Col. 2, line 27-
col. 4, line 37). Described advantages include controlled polymer functionality and molecular weight,
as well as lower polydispersity and increased percent incorporation of polyhydric alcohol molecules
(col. 4, lines 33-37; col. 7, lines 26-29; col. 8, lines 32-37). Production of energetic oxetane polymers
is also disclosed (col. 8, lines 38-40).
The examiner relies on the background discussion in Farooq for disclosing that it was well
known in the art to use oxonium salts having nucleophilic counterions to initiate cationic polymerization
of various monomers and obtain high molecular weight polymers (col. 1, lines 17-30) and that
triethyloxonium tetrafluoroborate is a known stable complex example thereof (col. 1, lines 40-44); and,
on the disclosure of Farooq for disclosing that such monomers include cyclic ethers, e.g., oxetanes and
tetrahydrofurans (col. 7, lines 37-45) as described in Wardle.
According to the examiner, it would have been prima facie obvious to combine two known
initiators of cyclic ethers, i.e., the catalyst of Farooq with the alcohol catalyst of Wardle, for their
recognized purpose of initiating polymerization of identical monomers because the catalysts are the
same type of chemical ingredients (answer, pages 5-10). According to the examiner, the artisan of
ordinary skill “would have a reasonable expectation of success that the
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