更新时间:01-07 上传会员:雨橙
分类:理工论文 论文字数:13906 需要金币:1000个
摘要:以甲醛和苯酚为原料,以NaOH为催化剂,制备出可发性酚醛树脂。研究了碱催化法合成酚醛树脂过程中原料配比、反应时间和反应温度对可发性酚醛树脂性能的影响。研究发现较优的参数选择应是苯酚/甲醛(摩尔质量)为1:1.6,反应温度为90~96℃,反应时间为1~2h。探讨了发泡剂和表面活性剂对发泡过程的影响,研究发现较优的发泡剂为三氟三氯乙烷,表面活性剂为吐温-80。通过酚醛树脂固化过程中的温度-时间变化曲线研究了树脂的反应活性,从而确定了发泡时的最佳温度为140~150℃,最佳发泡时间为6~8min。用制得的阻燃酚醛泡沫塑料进行了氧指数、垂直燃烧的性能测试。研究发现其氧指数在30~31%,垂直燃烧为FV-1级。利用热重分析仪器对酚醛泡沫塑料热分解特性进行了研究,体系为500℃时成炭率在60%以上。锥形量热分析可知苯酚/甲醛(摩尔质量)为1:2.0的酚醛泡沫塑料的阻燃性能较好。
关键词:酚醛树脂;酚醛泡沫塑料;阻燃性;微波发泡
Abstract:The phenolic resin was successfully synthesized with formaldehyde and phenol as raw material, NaOH as the catalyst.The influence of raw materials ratio, reactive time and temperature of base catalysis method on the properties of phenolic resin was studied. The optimal technological factors were raw materials ratio (Phenol/Formaldehyde) of 1:1.6, reactive temperature of 90~96℃ and reactive time of 1~2h.The effects of foaming agent and surfactant were studied. The optimal foaming agent is trifluorotrichloroethane and the optimal surfactant is twain-80. The reactive activity of phenolic foam was studied by the curve of temperature to time in the curing procedure of phenolic resin. We found that the reactive technological for foaming was140~150℃ and the reactive time for foaming was 6~8min. Then I test flame retardant performance of the flame retardant phenolic foam plastics, such as the LOI value, the UL-94 rating test. Study found that the LOI value is 30~31% and the UL-94 rating is FV-1 rating. The thermal decomposition of the phenolic resin was studied by thermo gravimetric analysis, when the temperature is 500℃ we found that the carbon rate is above 60%.The flame retardant performance of the flame retardant phenolic foam plastics was also studied by Cone calorimeter analysis,we found that (Phenol/Formaldehyde) of 1:2.0 was better than others.
Key words:phenolic resin;phenolic foam plastics; flame retardance;microwave foaming
本实验较为系统地研究了微波发泡酚醛树脂的制备过程,得到以下结论:
(1).酚醛树脂合成的最佳P/F的配方是1:1.6,PA/工业甲醛的最佳比例也是1.6:1。合成 时的最佳温度在96~100℃之间,最佳时间为1~2h。
(2).结合各个配方所制备出来的树脂的物理性能测试结果可以看出用于发泡的最佳酚醛树脂的固含量在80%左右,其最佳粘度在6000~7000mPa·s之间。对于发泡时所用试剂的研究表明,发泡时所选用的最佳发泡剂是三氟三氯乙烷,最佳的表面活性剂是吐温-80。由之前凝胶时间的测定得出最佳发泡温度在140~150℃,最佳发泡时间为6~8min。
(3).由酚醛泡沫塑料的阻燃性能的测试结果,可以知道其垂直燃烧性能级别为FV-1级,氧指数在30~31%之间。说明其阻燃性能良好,拥有一定的阻燃性,但是与实际现有的酚醛泡沫塑料的标准性能相比还有欠缺。由酚醛泡沫热失重分析看出P/F为1:1.9的样品失重少,残留多,阻燃性较好些。其他式样失重相对较大些,但是总体的阻燃性良好。样品基本都是在550℃左右时处于最高的失重速率,说明低于该温度下时酚醛树脂基本不燃烧。