Cyclic polymerizability

Sumida et al. (4) prepared cyclic polymerizable florinated norbomane monomers, (VII), suitable for photoresist materials which had high transparency in the light wavelength region from ultraviolet to near-infrared. 

Ethylene oxide and cyclic silicones represent an interesting group of monomers that might be polymerizable by an electron transfer process. The initiation would lead to the formation of... 

A novel polymerized vesicular system for controlled release, which contains a cyclic a-alkoxyacrylate as the polymerizable group on the amphiphilic structure, has been developed. These lipids can be easily polymerized through a free radical process. It has been shown that polymerization improves the stabilities of the synthetic vesicles. In the aqueous system the cyclic acrylate group, which connects the polymerized chain and the amphiphilic structure, can be slowly hydrolyzed to separate the polymer chain and the vesicular system and generate a water-soluble biodegradable polymer. Furthermore, in order to retain the fluidity and to prepare the polymerized vesicles directly from prev lymerized lipids, a hydrophilic spacer has been introduced. 

Before leaving the diacetylenes we must note some of the stereochemical varieties available in their polymers. Triynes, 138, also polymerize in the crystal by 1,4-addition (213). Also, cyclic di- and polyenes give polymeric products on irradiation. The exact structure of the polymer, however, has been established only in the polymer 135. Note that alternate side chains in this polymer are on opposite sides of the plane of the main chain the polymer is thus meso. However, in principle such a reaction could give rise to optically active polymers in suitable structures. The cyclic tetradiyne 139 crystallizes in a polymerizable phase containing interstitial chloroform (209). The polymerization reaction, which involves... 

It has long been accepted that cyclic ethers with more than four-membered rings are, in contrast to epoxides, only cationically polymerizable due to the high basicities of their ether oxygen atoms. The cationic polymerization involves 0-... 

Most cyclic monomers of interest in the field of composites happen to be heterocyclic in nature. Polymerizability of some monomers is summarized in Table 1.1. Ring opening polymerizations invariably follow ionic mechanisms, although a few are known to proceed via the free radical route and some via metathesis involving metallocarbene intermediates. 

Table 1.1 Polymerizability of Some Unsubstituted Cyclic Monomers...

Title Fluorinated Cyclic Compound, Polymerizable Fluoromonomer, Fluoropolymer, Resist Material Comprising the Same, and Method of Forming Pattern with the Same... 

Fluorinated Cyclic Compound, Polymerizable Fluoromonomer, Fluoropolymer... 

Fluorinated Cyclic Compound, Polymerizable Fluommonomer, Fluoropolymer Polymeric florinated norbomane - and terpolymers are illustrated below. 

Several factors are known to affect the ROP of cyclic esters. The main factors are the reaction conditions, i.e., the nature of the initiator, type of solvent and reaction temperature, and also the ring size of the monomer used and the substituents on the monomer ring [105-107] Cyclic esters of four-, seven-, and eight-membered rings polymerize, whereas the five- membered ester does not. In the case of six-membered rings, the polymerizability depends on the substituents [105],... 

Methylene- 1,3-dioxolane (15) is polymerized by peroxide initiator to produce a polyester 16 which is regarded as the product of the hypothetical ring-opening polymerization of the non-polymerizable heterocycle of y-butyrolactone (Eq. (14)).13). The opening of the cyclic species bearing a free radical 17 is the key step. 

Cyclic siloxane compounds containing an aliphatic unsaturation component and fluorinated alkyl groups were prepared in a two-step process with overall yields >53%. These polymerizable agents are characterized as having water and oil repellency in addition to weather, solvent, and chemical resistance. 

Additional polymerizable cyclic siloxane derivatives, (I), were prepared by the author [1] in a subsequent investigation. 

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