微波辐射下热塑性酚醛树脂的合成

Synthesis of Novolac Under Microwave Irradiation

首次将微波这种能量形式引入热塑性酚醛树脂的合成反应中,在详细分析了微波辐射下树脂合成特点的基础上,结合基础化学试验室的实际情况,以家用微波炉为基础,设计改装了一套能初步适用于热塑性酚醛树脂连续化试验的微波合成装置。利用此装置,采用微波直接辐射及水浴协同加热相结合的方式合成出壳法用热塑性酚醛树脂。结果表明,与传统加热相比,微波辐射下热塑性酚醛树脂聚合及脱水时间分别缩短了87 5%和74%左右,所得树脂流动性能及其覆膜砂强度也得到了显著改善。

For the first time, Novolac was synthesized under microwave irradiation. The characters of the synthesis process of the resin under microwave irradiation were analyzed in detail. According to the laboratory condition, a primary microwave device suitable for the uninterrupted experiment for novolac was modified based on domestic microwave ovens. Novolac for shell molding was gained under direct microwave irradiation and microwave irradiation associated with water bath using this device. The results showed that the polymerization and dehydration time was shortened about 87.5% and 74% respectively, furthermore, the fluidity of the resin and the strength of resin-coated sand were improved remarkably, compared to that by a conventional heating.