Radical cyclopolymerization

The free radical cyclopolymerization of diallylammonium compounds leads to linear water-soluble polymers containing predominantly pyrroli-dinium rings as the structural unit of the polymer chain [14,15]. This well-established principle of polymer synthesis was used for the synthesis of the polycarbobetaines from their zwitterionic monomers (route (1), see above), which are summarized in Scheme 1. 

Table I - Cyclization ratios in free radical cyclopolymerizations.

Table V - Calculated A AS and experimental AAS for the chain propagation reactions in the free radical cyclopolymerization of some monomers.

Intramolecular Addition Modes in Radical Cyclopolymerization of Some Unconjugated Dienes... 

The factors influencing intramolecular addition modes were investigated in detail in the radical cyclopolymerization of some unconjugated dienes. 

Thus, we investigated in detail the factors influencing intramolecular addition modes in the radical cyclopolymerization of some unconjugated dienes, including diallyl and dimethallyl dicarboxy-lates, acrylic and methacrylic anhydrides, and allyl -substituted acrylates and discussed the selectivity of reaction mode of intramolecular hh or ht addition in terms of the thermodynamical standpoint. The present article gives a summary of our recent work including published papers(18-23). 

Radical Cyclopolymerization of Divinyl Formal Polymerization Conditions and Polymer Structure... 

We have been conducting detailed structural studies on the cyclopolymers of several unconjugated dienes. Radical cyclopolymerization of dlvinyl ether had been known to give polymers with the unsaturated monocyclic unit and the bicyclic unit(1 2). Our Initial 13C-NMR study Indicated that the polymer was composed of the flve-membered monocyclic unit with the pendent unsaturation and the bicyclic unit with the bicyclo[3,3.0]octane skeleton(3). According to the stereochemistry of the polymer established by more recent NMR examination(4), the polymerization process was shown to be highly stereoselective. 

While ring-opening polymerization of camphorsultam was attempted futilely to prepare a new polymer containing a bicyclic structure and a new acidic sulfonamide group in the backbone [115b], radical cyclopolymerization was exploited in the synthesis of 193 nm alicyclic polymers (Fig. 79). Transannular polymerization to form polynortricyclene bearing tert-butyl ester was utilized in radical copolymerization with MA (Fig. 79) [275]. Radical cyclopolymer-... 

Attempts to prepare H-H poly(methyl methacrylate) by radical cyclopolymerization of methacrylic anhydride and methacrylimides have given promising results (42). The cyclopolymerization must be directed to the exclusive formation of the unfavorable five membered ring intermediate. Cyclopolymers which consist of mixtures of five and six membered rings were obtained with five membered ring intermediates predominating (23,42,59). 

Enantioselective Radical Polymerization. The 2,2 -azo(bis)isobutyronitrile/copper(n) triflate/chiral diamine ligand system was used as an asymmetric reverse atom transfer polymerization initiating system for the enantiomer-selective cyclopolymerization of (25,4S 2/ ,4/5-2,4-pentanediyl dimethacrylate. Results indicate that the asymmetric reverse ATRP initiating system was effective for the enantioselective radical cyclopolymerization, leading to optically active polymers. Three different chiral diamines were used as ligand including (—)-sparteine. 

Free-radical cyclopolymerization of diallyl or mixed allyl-vinyl and allyl-acrylic derivatives has been investigated. Particularly, Jansen has studied the photo-initiated copolymerization of various commercial vinylethers as well as allylethers with fumarates or maleates. Real-time infrared spectroscopy with advanced multivariate statistical techniques was used for the determination of copolymerization reactivity ratios of... 

Nakamura, M., Sugiyama, N., Etoh, Y, Aosaki, K., and Endo, J. (2001) Development of perfluoro transparent resins obtained by radical cyclopolymerization for leading edge electronic and optical applications. Nippon Kagaku Kaishi, 12, 659 -668. 

Shortly before I started research at Iowa, George Butler had demonstrated that certain non-conjugated dienes would undergo free-radical cyclopolymerization to afford soluble materials containing... 

Al-Phenyl-iV-allylmethacrylamide (23) gives a polymer with a five-membered ring structure with true asymmetric centers in the main chain by free-radical cyclopolymerization [63]. When the polymerization is carried out in the presence of SnCl4/(-)-menthol, the resulting polymer was optically active ([a]] -5.6°). Chiral induction was also observed in the copolymerization of 23 with MMA. Cationic cyclopolymerization of 24 using a ZnClJ 10-camphorsulfonic acid (25) initiator system gives an optically active polymer having a 1,3-dioxane structure in the main chain([a]435-17°)[64]. 

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