It was attributed to the introduction of flexible molecular units BFBH which contained aliphatic chains and amide group
. Combined with the FTIR results, this suggests that the polymerization proceeded was successfully.
Taking into account the microstructures of these copolymers, the intermolecular hydrogen bond between the carbonyl group of MMA and the amide group
of MAAM has a larger probability of occurring than the self-association through hydrogen bonding of pure PMAAM (15).
It was concluded that the interaction of water with nylon took place at the amide group
. Thus, it is not surprising that amide bonds are susceptible to hydrolysis, and this reaction represents the reverse of the polymerization reaction (4).
With the increase in AA contents, the voiding is obvious because the functional monomer (AA) was reacted with the end amide group
of PA 6 (Fig.
The molar intake is the number of solvent molecules divided by the number of amide groups
in the amorphous fraction (in which the sorption of solvents takes place), as shown in [E.sub.q] 2, where [M.sub.soIvent] is the molar mass of the diffusing molecule, [X.sub.c] = 38% is the crystalline fraction measured by DSC, and [M.sub.PA66] =113 g [mol.sup.-1] is the molar mass of polyamide per amide group
(PA66 has two amide groups
However, in the case of the amide group
, both the crystalline and amorphous peaks could be measured without problem.
The peak at 1706 [cm.sup.-1] represents the vC = O H-bond, which indicates the presence of hydrogen bonding between the urethane group of CPU coating and the amide group
of the PA6 fiber (14), (15).
On the other hand, the polymers having the aliphatic sequences of same type in the structure of macromolecular chains as in polyesters but linked only with amide group
(-NH-CO-), known as nylons are high-performance engineering plastics.
The IR spectra of all six compounds 4a-4f showed signal of carbonyl of amide group
around 1710-1693 cm-1 due to delocalization of lone pair of nitrogen atom in amide group
and a signal of NH stretch of amide at 3342-3265 cm-1.
As PA is a weak acid, a solvent with acidic properties can protonate the amide group
; consequently, the amide group
will have less possibility to establish hydrogen bonding with other chains.
 Bupivacaine is longer acting amide group
, which has been used as prime agent in epidural anaesthesia and also to provide postoperative pain relief.
The gel can be produced by dissolving a polyvinyl alcohol powder in an aqueous solution containing water or water and an organic solvent including a group selected from a hydroxy group, an amino group and an amide group
; and crosslinking by adding a crosslinking agent thereto.