Surface properties and hydrogen bonds of mono-functional polybenzoxazines with different N-substituents

Abstract

A series of mono-functional benzoxazine monomers with different N-substituents were synthesized from phenol, formaldehyde, and various amines (ammonia, methylamine, n-butylamine, dodecylamine), named P-am, P-m, P-b, and P-da, respectively. The surface properties of these polybenzoxazine films were proven by contact angle measurements. The hydrogen bond network of the polybenzoxazine systems was studied using the FTIR spectra. And the results showed that the surface free energy increased with increasing the fraction of intermolecular hydrogen bonding when the N-substituent was an alkyl chain. However, the rule was not suitable when the N-substituent was H. That was because there was one more kind of intramolecular hydrogen bond in the poly(P-am). Based on these findings, we proposed that both the N-substituent alkyl group and the fraction of intermolecular hydrogen bonding had effects on the surface free energy.

Benzoxazine Containing Fluorinated Aromatic Ether Nitrile Linkage: Preparation, Curing Kinetics and Dielectric Properties

“…It can be attributed to the fact that with the ring-opening of oxazine rings, the formation of H-bonds between intramolecular and intermolecular chains increased. This trends were well consistent with the published literatures [41,42].…”

“…The characteristic absorption observed at around 3289–3555 cm −1 can be mainly assigned to the intermolecular and intramolecular H-bonds, which were formed between the hydroxyl and nitrogen atoms generated from the ring-opening polymerization of oxazine rings [39,40]. As the references reported that the intramolecular H-bonds could turn into intermolecular H-bonds when the temperature went on which contributed to the increase of surfce free energy of cured matrix [41,42]. It was well known that the formation of hydrogen bonds was sensitive to temperature.…”

“…Figure 14a showed that poly(FAEN-Bz) cured at 280 °C possessed the highest dielectric constants (~5.0), which can be assigned to the polar hydroxyl existed in the matrix resin. The increasing of dielectric constant can be attributed to the two facts: (1) with the curing temperature went on the intramolecular H-bonds would turn into intermolecular H-bonds to increase the surface energy thus to increase the dielectric constants; (2) the H-bonds could be destroyed under high temperature to form free –OH to increase the dielectric constants [40,41]. In Figure 14b, low dielectric loss was presented and it’s obvious that dielectric loss was a frequency-independence parameter for poly(FAEN-Bz) cured at 240 and 260 °C, while for poly(FAEN-Bz) cured at 280 °C, the dielectric loss was frequency dependent.…”

Porous polymeric membranes with thermal and solvent resistance

“…The hydrophilicity of the DBD-POXI modified membranes can be attributed to the polar carbonyl groups. In addition, nucleophilic attack on DBD could occur on the carbonyl group, generating a -OH group, which would contribute to the hydrophilicity [44][45][46]. Figure 6.…”

Synthesis and Polymerization of Naphthoxazines Containing Furan Groups: An Approach to Novel Biobased and Flame-Resistant Thermosets

“…It is known that, in addition to the chemical structures, the hydrogen bonds present in the polyoxazines also play an important role in a wide variety of properties of these compounds. A number of studies have observed the existence of bonds of the type -OH⋯O, -OH⋯N, and -OH⋯π in poly(oxazines) and demonstrated that such bonds contribute to the improvement of their thermal properties, such as elevated glass transition temperatures [18][19][20]. Thus, the insertion of groups that promote the formation of these bonds in polyoxazine compounds is also a strategy for obtaining materials with improved properties.…”