By the scientists on a large scale it is accepted that AKD forms covalent bonds with cellulose through ester bonds
(Nahm, 1986; Lee and Luner, 2005; Davies et al.
These results can be explained by the facts that the sulfur atom on the thioester bond of the BPT polythioesters has larger radii than that in oxygen atom on the ester bond
of the BPH polyesters and, furthermore, lower polarity of the S--C bond in the thioester bond than that of the O--C bond in the ester bond
would induce more flexibility.
2]-macroglobulin family are unique for the presence of an internal thiol ester bond
, which in LAM links Cys-999 with Gln-1002 (Ikawi et al.
However, on a kinetic ground, the condensation reactions leading to polyester regradation are expected to be considerably slower because the probability that the free end groups react with a terminal rather than with an inner ester bond
of the polyester is very small: an effect of this type might probably be expected to occur only with the monomers whose vapor pressure is particularly high.
concentration in the polyester parts of the POU, expressed as the number of ester bonds
/the number of carbon atoms in a main chain per a polyester repetitive unit, is given in Table 5.
There was no apparent peak of an ester bond
in the native starch.
The viscosity drop is lowest for V-PET, sharper for CR-PET, and sharpest for PC-PET; in PC-PET it is evident that the presence of impurities catalyzes ester bond
2 where [ester](t) is the concentration of ester bonds
in the polymer matrix as a function of degradation time and [[ester].
Biocatalysts carried out various trials and finally came up with the enzyme Pectinase 872L which works by catalysing the hydrolysis of the methyl ester bonds
in pectin, releasing free carboxyl groups.
Others joined in the fray, pointing out that the arsenate ester bonds
that would be required to make arsenic-based DNA are unstable in water, with an estimated half-life of less than one second.