Vinyl hydrogen fumarate

When (67) was treated with a wide variety of cycloaddition reagents under various conditions, it behaved as a diene or a dienophile but not as a 1,3-dipole. As a dienophile it reacted with 2,3-dimethyl-1,3-butadiene to give (70) and with cyclopentadiene to give an analogous product. As a diene it reacted with [2.2.1] bicycloheptene to give (72), presummably via (71), by loss of carbon monoxide and hydrogen. No products were isolated when (67) was treated with maleic anhydride, dimethyl acetylene-dicarboxylate, diphenylacetylene, dimethyl fumarate, carbon disulfide, isobutyl vinyl ether, cyclohexene, and cyclopentene. 

Other heats of co-polymerization w hich are available include those between vinyl acetate and the two isomers diethyl fumarate and diethyl maleate. If the co-polymers derived in these two cases are identical, then the difference between their heats of co-polymerization should be equal to the heat of isomerization of diethyl maleate to diethyl fumarate. WilUams has measured the heats of hydrogenation of the two isomers in solution as — 33 5 rb 0 1 and — 29 3 rh 0 1 kcal/mole, respectively, so that the heat of isomerization is — 4 2 i 0 2 kcal/mole. The observed difference between the heats of co-polymerization is —-1 6 0 5 kcal/mole. The difference of 2 6 i 0 7 kcal/mole between this value and the heat of isomerization is well outside the combined experimental error. This difference might be accountable in terms of different heats of mixing of the monomers in the two systems, and differences in heats of solution in the hydrogenation reactions. On the other hand it may indicate that the vinyl acetate/dietliyl maleate and vinyl acetate/di-... 

Combinations of donor/acceptor systems, comprised of at least one multifunctional monomer, are actually capable of sustaining rapid fi ee-radical polymerization without external photoinitiators. Donor monomers can be vinyl ethers, N-vinylformamides, and N-vinylalkylamides. The acceptor monomers are maleic anhydride, N-arylmaleimides, N-alkylmaleimides, dialkyl maleates, and dialkyl fumarates. N-alkylmaleimides can participate in excited state hydrogen abstraction fi om diacrylates. The reaction proceeds either in the presence or in the absence of oxygen. ... 

On the other hand, Chickering and Mathiowitz prepared hard microspheres made of both fumaric and sebacic acid and found that these microspheres strongly adhered to the mucosa of a rat intestine. Because such material cannot interpenetrate, it is hypothesized that hydrogen bonding is the cause of mucoadhesion [3]. Mortazavi and Smart measured the adhesive force of disks made of various mucoadhesive materials using a DiaStron rheometer. They concluded that the interaction between the adhesive and mucous is not an important factor because the disk adhered more strongly to poly(vinyl chloride) (used as a reference) than to the rat intestinal mucosa [4]. 

---