Hydroxyl terminal groups

Various types of neutron scattering can be utilized to extract data on structure and dynamics for novel catalytic materials. By selectively deuterating an SSZ-13 zeolite, Cheetham and others" used ND performed on the Dual Beam Neutron Spectrometer (DUALSPEC) diffractometer at the Chalk River Laboratories and found that two acid sites are present in the unit cell of the zeohte. INS can be used to probe the mechanism of the catalytic reaction by looking at the change in the vibrational modes of the adsorbed molecules on the surface. Lennon et alP found that the interaction of HCl with a ]-alumina catalyst results in the dissociative adsorption of HCl, in which the hydroxyl groups terminally bound to A1 are replaced by chlorine. INS spectra reveal an in-plane deformation mode, 5 (OH), that can be resolved into two bands located at 990 and 1050 cm. ... 

Wwwa/wm/wwwv OCH2CHOCOCH2CH2COOCH2CH2OH primary hydroxyl group terminated polyether... 

Urethane elastomers suitable for peroxide vulcanization typically are prepared from a hydroxyl-group-terminated oligomeric adipate polyester and 4,4 -methylenediphenylisocyanate (MDI). A typical structural representation is as follows ... 

The basic materials are monopolymers or copol)miers that react through terminal hydroxyl groups, terminal carboxyl groups, vinyl groups, or a combination of these materials. 

Peroxide Vulcanization of Urethane Elastomers. Urethane elastomers suitable for peroxide vulcanization are typically prepared from an hydroxyl-group-terminated oligo-... 

Macroinitiators such as polymeric Li, Na, and K alkoxides can also be used for the initiation of the six-membered cyclic carbonate polymerization. Thus, besides living vinyl polymers, hydroxyl group-terminated polymers of poly (tetrahydrofuran) (PTHF), poly(oxyethylene), and poly(dimethylsiloxane) (PDMS) were transformed to alkoxides by treatment with scc-BuLi or K-naphthalene and used as initiators. The use of these macroinitiators enables the identification of side reactions, as shown by Keul and Hocker for polystyrene lithium (PS Li ). The addition of the macro initiator to the monomer, to maintain a high excess of monomer, minimizes side reactions. Transformation of the polystyryl... 

It is worth mentioning that instead of homopolymers also random copolymers may constitute the blocks. Feijen s group used a hydroxyl group-terminated random copolymer - poly (TMC-co-caproIactone) - instead of homopolycarbonate. ... 

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