Cationic Polymerization of Phenylbutadienes. III. Cationic Polymerization of 2-Phenyl-1,3-butadiene

Abstract

ABSTRACT:2-Phenylbutadiene was polymerized by SnC14, BFaOEt2, and PhsCSnCls in ethylene dichloride. The kinetic study showed a rapid initiation in the cases of SnC14 and BF30Et2, but a rather slow initiation in the case of PhaCSnCls. The initial rate of polymerization in the cases of SnCl4 and BFaOEt2 or the maximum rate in the case of PhaCSnCls was expressed as followsThe molecular weight of the polymers obtained in these cationic polymerizations was independent of concentrations of both monomer and catalyst; hence, the monomer chain transfer was proposed as a terminating reaction. By IR, UV, and NMR spectroscopies, it was shown that the microstructure of the polymers obtained in these cationic polymerizations was a 1,4-structure and about a half of the double bonds in the polymers was consumed by a novel cyclization whose scheme was proposed. The UV spectrum of the propagating species of 2-phenylbutadiene in the cationic polymerization was also found to be the same as in the case of 1-phenylbutadiene.

Cationic polymerization of 1,3‐pentadiene I. infrared, 1H‐NMR and 13C‐NMR investigations on the microstructure of poly(1,3‐pentadiene) synthesized with cationic catalysts

“…Asami et al (Refs. 10,11,18,19) were interested in various alkyl-and cnyl-butadienes among which the piperylene whose cationic polymerization was the object of few systematic investigations (Refs. 11,(20)(21)(22)(23).…”

Cationic Polymerization of Phenylbutadienes. 6. Cationic Polymerization of Methylpheny-1,3-butadienes

“…The entropy difference was the greatest in the BF3OEt2-toluene system or in the SnCU-TCA-methylene chloride system but was small under other conditions. In general, propagation reaction in cationic polymerization may be assumed to be subdivided into the following two elementary reactions shown in eq 3, i.e., the formation of xcomplex between propagating end and monomer, and the subsequent step changed from x-complex into -bond formation by the attack of the propagating end to a monomer.32 Pn + A" + ^(P"M)+ A-Pn+i+ A- (3) step 1 step 2…”

“…2-Methyl-1-phenyl-l,3-butadiene (2-Me-l-PB)16 was prepared from the corresponding diazonium salt and isoprene through Meerwein arylation and subsequent dehydrochlorination, bp 89 °C (12 mm). 3-Methyl-l-phenyl-l,3-butadiene (3-Me-l-PB),17 1-phenyl-l,3pentadiene (1-PPD),17 1 -methyl-2-phenyl-1,3-butadiene (l-Me-2-PB),18 and 3-phenylisoprene (3-Me-2-PB)19 were prepared by the Grignard reagents with benzalacetone, cinnamic aldehyde, propiophenone, and acetone, followed by hydration and subsequent dehydration, respectively. The boiling points of these monomers were as follows: 3-Me-l-PB, 83-85 °C (7 mm); 1-PPD, 101 °C (12 mm); 1-Me-2-PB, 73-76 °C (13 mm); 3-Me-2-PB, 80-85 °C (23 mm).…”

Copolymerization of 1,3-butadiene with phenyl/phenethyl substituted 1,3-butadienes: a direct strategy to access pendant phenyl functionalized polydienes

“…Such as 1-phenyl-1,3-butadiene (PBD), it may follow the polymerization patterns of a 2-vinyl substituted styrene to form isomer "a" or of a 1-phenyl substituted 1,3-butadiene to form isomers "b-e" (Scheme 1). Up to date, many methodologies have been reported to polymerize PSBD, including anionic, 21,22 cationic, 23,24 and radical polymerizations. [25][26][27] Whereas the coordination polymerization was less investigated, in spite of the high stereoselectivity it usually possessed.…”