ADC的合成及纳米粒子复配ADC发泡剂的制备

Preparation of ADC and composite blowing agent consisting of ADC and nano-inorganic particles

以水合肼和尿素为原料直接缩合得到联二脲,后经双氧水氧化制得发泡剂ADC.研究了合成联二脲最佳工艺条件,并优化了发泡剂ADC的合成条件.采用溶胶-凝胶法制备纳米ZnO-SiO2粉体,并将该粉体加入到所制发泡剂中,制备了适用于PVC树脂的复配发泡剂.研究结果表明,合成联二脲的最佳工艺条件为:尿素与水合肼物质的量之比为4∶1,103℃下反应8 h,产率为94.1%;发泡剂ADC的最佳合成条件为:溴化钠和尿素的加入量分别为联二脲质量的8.16%和5.08%,65℃下反应5 h,双氧水滴加速率0.22 mL/min,ADC的产率为95.2%,纯度95%;复配发泡剂的分解温度低于PVC树脂塑化温度,符合PVC树脂的加工要求.

Biurea was synthesized from hydrazine hydrate and urea by means of condensation reaction, and blowing agent ADC was synthesized from biurea through oxidation reaction. Synthesis conditions of biurea and blowing agent ADC were optimized. The ZnO-SiO2 nanopowder was synthesized by sol-gel process, and applied in the prepared blowing agent ADC to obtain the composite blowing agent for PVC resin. The study results show that when mole ratio of urea to hydrazine hydrate was 4 ＂ 1 the yield of the synthesized biurea was 94.1% through reacting for 8h at 103 ℃. While adding amount of sodium bromide and urea were 8.16 % and 5.08 %, respectively, relative to biurea weight, and the feeding rate of hydrogen peroxide was 0.22 mL per minute, the yield of the resultant ADC product was 95.2 % and the purity was 95% through reacting for 5h at 65 ~C. The composite blowing agent was suitable for blowing process of the PVC resin because its decomnosition temperature was slightly lower than the melt-processing temperature of the PVC.