Hydrogenation of nitrile rubber using a new homogeneous palladium (II) catalyst: Synthesis and characterization

Abstract

Solution of 5 g samples of NBR substrates in 100 mL of CHCIB and 0.3 m mole of catalyst were introduced into a glass liner in order to minimize the corrosion inside the autoclave. The liner was

Hydrogenation of cis‐1,4‐polyisoprene catalyzed by Ru(CHCH(Ph))Cl(CO)(PCy3)2

“…11 However, for cis-1,4-polyisoprene, RuCl 2 (PPh 3 ) 3 was not active toward the hydrogenation (only 25% olefin conversion was attained after 5 h of reaction). The hydrogenation of CPIP using -C 3 H 5 Ru(CO) 3 Cl as catalyst was examined; however, it was only possible to achieve 48% hydrogenation after 5 h of reaction, and furthermore, this catalyst system led to degradation of the polymer chain and isomerization. 1,2-Polyisoprene was produced during the reduction process; its IR spectrum shows a characteristic peak at 968 cm…”

“…It is seen that Ru(CHA CH(Ph))Cl(CO)(PCy 3 ) 2 , Ru(CHACH(Ph))Cl(CO)-(PPr 3 i ) 2 , RuCl(CO)H(PPh 3 ) 3 , and RuCl(CO)(PhCO 2 )-(PPh 3 ) 2 had similar activity (86 -93% olefin conversion after 5 h) with respect to the catalytic hydrogenation of CPIP. One of the easiest ruthenium complexes to prepare is RuCl 2 (PPh 3 ) 3 , which has been found to be an efficient catalyst for hydrogenation of polybutadiene under mild conditions. 11 However, for cis-1,4-polyisoprene, RuCl 2 (PPh 3 ) 3 was not active toward the hydrogenation (only 25% olefin conversion was attained after 5 h of reaction).…”

“…One of the easiest ruthenium complexes to prepare is RuCl 2 (PPh 3 ) 3 , which has been found to be an efficient catalyst for hydrogenation of polybutadiene under mild conditions. 11 However, for cis-1,4-polyisoprene, RuCl 2 (PPh 3 ) 3 was not active toward the hydrogenation (only 25% olefin conversion was attained after 5 h of reaction). The hydrogenation of CPIP using -C 3 H 5 Ru(CO) 3 Cl as catalyst was examined; however, it was only possible to achieve 48% hydrogenation after 5 h of reaction, and furthermore, this catalyst system led to degradation of the polymer chain and isomerization.…”

“…Ruthenium complex catalysts, although considerably cheaper than the rhodium complex catalysts, are known to be excellent catalysts for hydrogenation of diene unsaturation; however, the activity of the ruthenium complexes are often not as high as rhodium catalysts for double-bond hydrogenation in the backbone of the polymer and lead to unfavorable crosslinking reaction for certain copolymers. One of the easiest ruthenium complexes to prepare is RuCl 2 (PPh 3 ) 3 , and it is an efficient catalyst for hydrogenation of polybutadiene. 11 Kinetic studies of PBD and NBR hydrogenation have been carried out by using RuCl(CO)(OCOPh)(PPh 3 ) 2 as catalyst under an atmosphere of hydrogen pressure and mild temperature.…”

Homogeneous Catalytic Hydrogenation of Polymers

“…Some examples of the hydrogenation of unsaturated rubber catalyzed by palladium complexes have been reported by Bhattacharjee et al [74][75][76][77][78]. When palladium acetate ((CH 3 CO 2 ) 2 Pd) was used as a catalyst for the hydrogenation of NBR [74] and styrene-isoprene-styrene triblock copolymer (SIS) [75], the catalyst showed good selectivity.…”