Epoxide monomers

Crystallinity is low the pendent allyl group contributes to the amorphous state of these polymers. Propylene oxide homopolymer itself has not been developed commercially because it cannot be cross-baked by current methods (18). The copolymerization of PO with unsaturated epoxide monomers gives vulcanizable products (19,20). In ECH—PO—AGE, poly(ptopylene oxide- o-epichlorohydrin- o-abyl glycidyl ether) [25213-15-4] (5), and PO—AGE, poly(propylene oxide-i o-abyl glycidyl ether) [25104-27-2] (6), the molar composition of PO ranges from approximately 65 to 90%. 

Complex formation in binary systems under the influence of organotin monomers (organotin carboxylate and epoxide monomers) was studied by IR and NMR techniques 2,3,18 -23). 

Organotin epoxide monomers 30,100 104) containing fairly reactive oxirane rings and both C=C and Sn—C bonds can be used as starting components for the synthesis of new polymers, chemically active stabilizers and biocides for polymeric materials, e.g. for PVC. 

In contrast to the above-mentioned organotin epoxide monomers, di-alkyl(diphenyl)allyl-2,3-epoxypropylstannanes with the general formula R... 

Bis(4- and 3-hydroxyphenyl)-l,3,4-oxadiazoles were alkylated in an excess of epichlorohydrin in the presence of NaOH and quaternary ammonium salts, while the temperature was gradually raised from 20 to 90 °C, affording luminescent epoxide monomers (Scheme 17) <1999CHE358>. 

Epoxide derivatives of 2,5-bis-oxyphenyl-l,3,4-oxadiazoles and fluorescein, which are luminescent epoxide monomers, were synthesized and their luminescence properties were studied <1999CHE358>. The excited state intramolecular proton transfer reactions and luminescent properties of the ort j-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole were elucidated to conclude that the proton phototransfer reaction is very efficient in the studied... 

The above mechanistic study suggested that to construct monomers more reactive than I, the monomer should bear highly reactive epoxycyclohexyl groups, but should not contain ester or other nucleophilic groups. Accordingly, we initiated a program to prepare such a novel senes of difunctional epoxide monomers. Shown in equations 6 and 7 is the synthetic method which was employed. 

McKelvey etal. (1959) investigated the reaction of epoxides with cellulose in alkaline conditions, reporting that alkaline cellulose reacted readily once the concentration of sodium hydroxide was sufficiently high. However, no evidence was found of reaction between cotton yarn and cellulose with a range of epoxides under a variety of reaction conditions. It was concluded that the apparent reactivity of cellulose with epoxides was primarily due to alkaline swelling of the cellulose, self-polymerization of the epoxide monomers then occurring within the interior structure of the fibres. It was also noted that the reactivity with phenol OH groups was very low (e.g. only 1 % conversion of ethylene oxide with various phenols). 

Propagation with the anionic coordination initiators, especially the aluminum and zinc initiators such as aluminum isopropoxide or the metalloprophyrins such as VI, involves covalent propagation in which the epoxide monomer is inserted into a metal-oxygen bond [Penczek and Duda, 1993 Penczek et al., 1995 Szwarc and Van Beylen, 1993] (Eq. 7-9). The propagation is categorized as an anionic coordination process since one can visualize... 

Diaminodiphenyl sulfone (DDS) cured tetraglycidyl-4,4 -diaminodiphenylmethane (TGDDM) epoxies are the mpst common composite matrices utilized in high performance fibrous composites prepared from prepregs. The structures of the unreacted TGDDM epoxide and DDS monomers are illustrated in Fig. 3. The TGDDM epoxide monomer is a liquid at 23 °C, whereas the DDS monomer is a crystalline... 

Propylene oxide represents a very attractive epoxide monomer for copolymerization with C02, as polypropylene carbonate) is industrially valuable. The low glass transition temperature (Tg) of 313 K, the sharp and clean decomposition above 473 K, and biodegradability of this copolymer are the reasons for its attracting interest in several applications. On a similar basis, H NMR spectroscopy is useful for assessing the coupling products resulting from the reaction of PO and C02 (Figure 8.21). 

As a second example, there is a wide variety of breakdown products and oligomeric products that may be formed from the reactive monomers that are the building blocks of plastics. For plastics, the general assumption has been that any side-reaction products and breakdown products are likely to be significantly less toxic than the monomers, and so restricting the migration of the monomer was accepted as an indirect way to limit any hazard from the oligomers also. Whilst this approach is probably acceptable for addition polymers, such as those made from the unsaturated monomers vinyl chloride, butadiene and acrylonitrile where the unsaturated monomer is far more noxious than their products, the validity of this means of indirect control is questionable for condensation polymers such as polyesters and for polyethers formed from epoxide monomers. 

The coordination polymerisation of cyclic ethers has been limited to those containing a three- and four-membered ring in the molecule. However, most of the literature data reporting on the homopolymerisation and copolymerisation of cyclic ethers in the presence of coordination catalysts concern epoxide monomers (Tables 9.1 and 9.4). 

Epoxide polymers exhibit stereoisomerism originating from the chirality of tertiary carbon atoms present in the polymer main chain. The stereoisomers of epoxide polymers are therefore tactic polymers their tacticity is connected with the structure of epoxide monomers undergoing polymerisation. Epoxide... 

Philo M R, Damant A P and Castle L, 1997, Reactions of epoxide monomers in food simulants used to test plastics for migration. Food Additiv. Contam. 14 (1), 75-82. 

Various bifunctional resins are based on acrylic epoxide monomers. Such systems can photopolymerize by the radical and/or cationic mechanism. With iron arene photoinitiators in the presence of an oxidant, radical as well as cationic photopolymerization of these monomers is possible . Onium -type photoinitiators form radical species upon photolysis, as shown in Figs. 3 and 4. The local radical concentration is, however, too low to permit the polymerization of such systems... 

Different techniques have been used to study the products of photoreactions of organometallic compounds for example, irradiation of the arene complexes [CpFe() -arene)]+ resulted in the substitution of the arene by solvent or other potential ligands present in solution. In solutions containing an epoxide monomer, this photochemical reaction generated a species that initiated polymerization. Ion cyclotron resonance Fourier transform mass spectrometry and electrospray ionization mass spectrometry were used to elucidate the mechanism of these photoinitiated polymerizations. 

The total theoretical heat of polymerization assuming conversion of all the epoxide functions to polymer was calculated to be 85 J/g. This was calculated from heats of reaction for cycloaliphatic epoxide monomers of 94.5 KJ/mol. 

Low-viscosity epoxide monomers are available which have high boiling points and low vapor pressures. However, the nature of the curing process involves conditions conducive to evaporation. The coating is applied in the form of a thin film with a very large surface. It is subjected to radiation from a high-intensity mercury arc which includes significant infrared radiation. 

We report here on the thermo-klnetlc analysis of the homo-polymerlzatlons of several epoxide monomers using a unique class of cationic Initiators, bls-trlfluoromethanesulfonyl methane and its derivatives. In addition we have Included standard Lewis and Bronsted acids, which has allowed us to observe some Interesting catalyst transformations. 

Upon irradiation, ferrocenium salts lose their arene ligands leading to generation of iron-based Lewis acids that coordinate with epoxide monomers. One of the monomers undergoes ring opening followed by addition of a new monomer. Arene... 

Employment of hybrid monomers consisting of epoxide and a functional group (usually vinyl ether) with high reactivity instead of conventional epoxide monomers [120,121,135,136]. 

Crivello s group followed either or both of two strategies that described for the additives in acceleration of photoinitiated cationic polymerization of epoxide monomers. These are stabilization of free radicals and cations by resonance and inductive effect, and the activated monomer mechanism. Comparative studies of novel monomers with conventional monomers show that newly designed monomers given in... 

Monomers possessing 1 -propenyl ether groups are reported to be the most reactive class of monomers toward cationic species. Therefore, a series of hybrid epoxide monomers with 1-propenyl ether group was designed and their behavior in cationic photopolymerization initiated by a diaryliodonium salt was investigated [120]. The... 

J.V. Crivello and R.A. Ortiz, Benzyl alcohols as accelerators in the photoinitiated cationic polymerization of epoxide monomers. J Polym. Sci. A Polym. Chem. 2002, 40(14), 2298-2309. 

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