Cationic polymerization of penta-1,3-diene

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with tBuCl/TiCl4 Initiating System: Kinetic and Mechanistic Study

“…A further increase of the t BuCl content in the system barely influences the reaction rate. It should be noted that the dependence of the polymerization rate on the t BuCl concentration is substantially distinguished from those for protic initiators/TiCl 4 initiating systems . For example, for the cationic polymerization of 1,3‐pentadiene with the trichloroacetic acid (CCl 3 COOH)/TiCl 4 initiating system, the maximal reaction rate is observed at a CCl 3 COOH/TiCl 4 molar ratio in the range of 2–10 (Figure S1, Supporting Information), while for H 2 O/TiCl 4 system—at a H 2 O/TiCl 4 molar ratio between 0.35 and 0.5 …”

“…The decrease of the unsaturation of the poly(1,3‐diene)s during the cationic polymerization is usually explained by an intramolecular cyclization leading to a rigid polymer backbone . However, for the cationic polymerization of 1,3‐pentadiene with the t BuCl/TiCl 4 initiating system, the intramolecular cyclization is unlikely.…”

“…It is known that the cationic polymerization of 1,3‐pentadiene is co‐initiated by a wide range of Lewis acids such as AlCl 3 , FeCl 3 , SnCl 4 , BF 3 OEt 2 , VOCl 3 , and TiCl 4 . The main feature of TiCl 4 ‐based initiating systems is their low activity in the polymerization of 1,3‐dienes in the absence of purposely added initiators such as water, hydrochloric acid, organic acids, and so on, while the addition to the system of protic compounds or cationogens allowed to increase the rate of polymerization of 1,3‐dienes significantly .…”

“…The main feature of TiCl 4 ‐based initiating systems is their low activity in the polymerization of 1,3‐dienes in the absence of purposely added initiators such as water, hydrochloric acid, organic acids, and so on, while the addition to the system of protic compounds or cationogens allowed to increase the rate of polymerization of 1,3‐dienes significantly . The TiCl 4 ‐co‐initiated cationic polymerization of 1,3‐dienes in conjunction with water, acetone, trichloroacetic acid, trifluoroacetic acid, tert ‐butyl esters of these acids, cumyl acetate, cumyl methyl ether, dimethylallyl bromide, and dimethylallyl alcohol has been investigated. The obtained poly(1,3‐diene)s are characterized by reduced unsaturation that was explained either by intramolecular cyclization or branching due to the chain transfer to polymer .…”

A new insight into the mechanism of 1,3‐dienes cationic polymerization. II. Structure of poly(1,3‐pentadiene) synthesized with tBuCl/TiCl4 initiating system

“…PPDs synthesized by cationic polymerization possess the most complicated microstructure of the polymer chain . Cationic PPDs are characterized by reduced unsaturation, which is explained either by chain transfer to polymer with the formation of branched structures or by intramolecular cyclization . The literature data on the microstructure of unsaturated part of polymer chain of cationic PPDs are quite ambiguous.…”