The lack of crystallinity and minimal hydrogen bonding in the polymers in table 4 allows for the examination of the effects of electronegative
can be reduced by the hydroxyl end group of PVP, Au nanoparticles do not attach on the P(AN-co-VA) microspheres due to the weak attraction between the electronegative
-CN and negative [AuCl.
It is possible to reduce CTC by incorporating electronegative
fluorine groups on the polymer backbone or incorporating bulky electron withdrawing substituent groups, as they restrict the inter-chain conformational mobility and thus lower the CTC [9, 35-37].
In this context, a chemical interaction might be formed at the wood/PVC interface according to Lewis acid-base theory (61): When exposed to chlorine atoms of PVC, the amino-silane treated wood veneer may chemically react and form an ionic bond with the matrix because of the highly electronegative
nature of chlorine atoms of PVC (23).
Sulfonation reactions are typical electrophilic substitutions when more electronegative
atoms of oxygen draw the electron density from the sulfur atom, which then becomes an electrophilic center.
Even if the C-F link is the most electronegative
bond involving carbon, its dipole is lower than that of the C-O-H group.
Note that methyl groups attached to electronegative
atoms like O or -CF- have lower values of E-state index S (S < 2.
Since these atoms are increasingly electronegative
towards the upper right of the periodic table, they may share a lack of ability to enter into condensation reactions that involve the delivery of a hydrogen atom.
It replaces hydrogen because of its small size but it also brings with it electronic effects since fluorine is an electronegative
element--it just pulls electrons from its surroundings.
Lewis acids attract electronegative
atoms as well as perturb the orbitals of unsaturated carboxylic acids.
As can be seen, compound 2 presents a deep red electronegative
zone around the hydroxyl group (left side of molecule) and a second one in de vicinity of C-14 due to the presence of a double bound which shares electron density.
The introduction of a fluorine atom into a molecule is known to impart unique properties due to its highly electronegative
nature and small size.