Study On Ablative Matrix Resins Based On Benzoxazine For Resin Transfer Molding (RTM)

According to the requirements of RTM process for matrix resin and the characteristics of the polybenzoxazines, several novel ablative matrix resins based on benzoxazine for RTM were prepared, which have low viscosities but high char yieldsFirstly, according to the flexibility of molecular design of benzoxazine, four benzoxazine monomers were designed and synthesized. The four monomers were bifunctional benzoxazine (B-BOZ) which synthesized from aromatic diamine, phenol and formaldehyde, 3-(3-ethynylphenyl)-3,4-dihydro-2H-1,3-ben- zoxazine (EP-BOZ) which synthesized from formalde- hyde, phenol and 3-ethynylaniline, 3-aldehydicphenyl-3,4-dihydro-2H- 1,3-benzoxazine (AS-BOZ) which synthesized from formaldehyde, 4-Hydroxybenzaldehyde and amine and (15Na-BOZ) which synthesized from amine, formaldehyde and 1,5-binaphthol. The structures of these monomers were characterized by means of FTIR and ~1H NMRAccording to the requirement of the RTM process for matrix resin and the ablative resin,Take the B-BOZ as the basic component of resin, the process characteristics of the BB precursor were investigated by means of Brookfield viscometer. It was soften and can be flowed when heated to temperature above 50℃, its initial viscosity at 90℃ was 270cp and was only 340cp after 240 min. These results showed that the BB can be used as resin matrix for RTM technology. AS-BOZ is solid at room temperature ,which will be melt at 89℃,the initial viscosity of liquid at 90℃ was 108cp and was only 121cp after 240 min. the initial viscosity...