Research And Development Of The Full Bio-based Benzoxazine Resin

With increasing consumption and shortage of petroleum resources, world petroleum pricesare successively escalated. Therefore, industrial development of petrochemicals and polymermaterials in our country faced the tremendous pressure. The sustainable growth in the materialindustries came to a real problem crying out for solutions. A very important strategy for thisproblem is searching for new resources able to be an effective candidate of the petrochemicals.The materials what produced from the renewable raw materials (Bio-based materials), have beenattached great importance as their inexpensive, reusable, and inexhaustible characteristics.However, development of most of the bio-based materials is limited because they are preparedfrom starch or food oils, and have drawbacks in mechanical property and thermal stability due tothe lack of benzene structure in their molecules. Polybenzoxazines attract much attentionrecently as good thermal setting resins due to their attractive and useful properties: low meltviscosity, excellent mechanical properties, high glass transition temperature, low flammability,no liberation of byproducts, near-zero shrinkage upon curing, high chemical retardence, andextraordinary molecular design flexibility compared with other polymers. Almost ofbenzoxazines are prepared from petroleum-based raw materials.Based on this background, this work used the molecular design flexibility of benzoxazine todevelop a new class of fully bio-based thermosetting resin as a part of composite materials.In the present work, benzoxazines have been synthesized by various bio-based rawmaterials such as furfurylamine, octadecylamine, guaiacol, and cardanol. The chemical structuresof the products were analyzed by FTIR, NMR and elemental analysis. After the polymerizationor copolymerization of the benzoxazine monomers, the thermal stabilities of the benzoxazineresins were examined by DSC and TGA. The results showed that the bio-based benzoxazineresins have high thermal stability, some shortcomings of the bio-based resins are reparable bycopolymerization of two or more benzoxazine monomers. It was also found thatmethyl-p-toluenesulfonate (PTSM) has obvious effect on catalyzing the ring-openingpolymerization of the bio-based benzoxazines, as a significant decrease in the temperature ofbenzoxazine polymerization was observed. This result means a favorable improvement onprocessing of composite materials. The significance of the present study is the utilization of bio-based raw materials to takeplace of oil products to synthesize polybenzoxazine resins, and the development in bio-basedmaterials and environmental protection.