低残余单体酚醛泡沫的研究

Abstract

［中文文摘］针对如何降低酚醛泡沫中的残余单体(游离酚、游离醛)进行了研究.考察了不同酚醛比,反应温度,碱催化剂用量对残余单体的影响;添加尿素作为甲醛捕集剂对降低游离甲醛效果明显;采用醛酚比为 2.2,反应温度为 92℃,添加少量尿素(3 g尿素/100 g苯酚),制备出游离酚为 0.09%,游离醛小于 0.1%的酚醛泡沫,且其物理化学性能与通常条件下制备的酚醛泡沫无明显差异.［英文文摘］Phenolic foam is made by heating a mixture of a resol,a liquid blowing agent,a surfactant,and an acid catalyst,which initiates a condensation reaction.Compared with rigid plastic insulation materials such as polystyrene,polyurethane,and polyethylene, phenolic foam has low smoke and flammability properties,which make it an excellent candidate for use in buildings ,ships,and aircraft with promising developments in materials and new processing techniques.However,phenolic foam contains overly high contents of f ree phenol and free formaldehyde. We carried out a series of experiment s on different conditions. Free phenol was characterized by iodimet ry ,and free formaldehyde by hydroxylamine hydrochloride method. The effect of phenol/ formaldehyde molar ratios and reaction temperature on the content s of remnant monomers was discussed. The effect of adding urea on the content s of free form aldehyde was investigated. The effect of dosage of catalyzer was discussed. Under the condition at 92 ℃, CF / CP mole ratios of 2. 2 with a little urea (3 g urea/ 100 g phenol) ,phenolic foam in which the content s of f ree phenol was 0. 09 % ,and free formaldehyde was less than 0.1 % and cont rast with phenolic foam that prepare under normal condition , the performance of physics and chemistry doesn’t obvious difference have been successfully prepared.