一种可低温发泡酚醛树脂的制备

Preparation of Phenolic Resin Foaming at Low Temperature

以可低温发泡酚醛树脂（PF）为研究对象，分别采用气相色谱法和盐酸羟胺法研究了初始甲醛／苯酚物质的量之比（F／P）、反应温度和时间及催化剂NaOH用量等合成条件对PF游离酚和游离醛含量的影响。结果表明，F／P为1．5，NaOH用量为苯酚质量的3％，且在高温86℃和低温70℃各反应60min后，所制备的可低温发泡PF具有较低的游离醛含量，其黏度为2500～3000mPa·S，游离酚的质量分数为4．5％～5．5％，游离醛的质量分数为0．5％～0．8％。在5—10℃的低温条件下，向所制备的可低温发泡PF中依次加入表面活性剂、发泡剂、固化剂，通过泡沫板材生产线发泡制备了PF泡沫保温板，其表观密度、导热系数、氧指数、吸水率、尺寸变化率、压缩强度和拉伸强度完全满足国家标准要求，可应用于外墙保温材料。

Phenolic resin （PF） foaming at low temperature was taken as subject of research, then effects of synthetic conditions such as initial molar ratio of formaldehyde and phenol （F / P）, reaction temperature and time, content of NaOH catalyst on free phenol content and free aldehyde content of PF were studied by means of gas chromatography and hydrochloric acid hydroxy amine method. The results indicate that when F/P is 1.5, the content of NaOH is 3% of phenol mass and the synthetic process is divided into reacting at high temperature of 86 ~C and low temperature of 70℃ each for 60 minutes, the free aldehyde content of the synthetic PF is lower （0.5%-0.8%）, and the viscosity is 2 500-3 000 rnPa. s, free phenol content is 4.5%-5.5%. On the basis, the PF foam insulation board was prepared in PF foam board production line through adding surfactant, foaming agent and curing agent into the synthetic PF in turn at low temperature of 5-10 %, it＇ s apparent density, coefficient of thermal conductivity, oxygen index, water absorption, dimensional change rate, compressive strength and tensile strength can meet the requirements of PRC standards and be applied to exterior wall insulation material.