Study On Preparation And Properties Of Benzoxazine/Montmorillonite Nanocomposites

In this paper, Benzoxazine(BZ) was synthesized from formaldehyde, aniline and phenol. The order of material addition, the reaction temperature and the reaction time are studied. The conditions of preparation are as follows: mixing formaldehyde and aniline before adding phenol, 115-125℃, 2.5h.Organic-montmorillonite(OMMT) was obtained by an ion-exchange reaction between Na-montmorillonite(MMT) and hexadecyl trimethyl ammonium bromide(CTAB). Then Benzoxazine/montmorillonite nanocomposites(BZ/MMT) were prepared by two different methods, namely melting intercalation and solution intercalation. As a result, melting intercalation was preferred because it has reduced the cycle of the production and made the products less expensive, compared with solution intercalation. Benzoxazine/montmorillonite nanocomposites(P-BZ/MMT) was obtained by reverse-phase suspension polymerization without any cross-linker, initiator and dispersing agent. Then FT-IR,XRD,transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to analysis the structure of nanocomposites and the dispersion of OMMT in BZ matrix. It was proved that MMT were dispersed into BZ in nanoscale. The result of TG showed that BZ/MMT have higher thermal stability than BZ. The curing process of BZ and BZ/MMT were studied by non-isothermal differential scanning calorimetry (DSC) at different scanning rates. Various kinetic parameters and apparent activation energy for both curing systems were obtained by using Avrami equation. It was found that the OMMT treated played a vital role in curing behavior of BZ/MMT system and two types of curing reactions occurred in BZ/MMT system which includes: catalyzed polymerization and thermal polymerization. As a result, big difference in the two systems occurred at the characteristic curing temperature, curing rate, the heat of reaction, reaction order, as well as apparent activation energy.The activated carbon/montmorillonite nano-absorbent was prepared from P-BZ/MMT through carbonized and activated. According to orthogonal test method, we analyzed what optimize these operation conditions is. The adsorption of alkaloid,...