【摘要】 我国将壳法酚醛树脂的软化点作为区分其牌号的标志性指标。软化点的测定虽都采用环球法,但加热介质、升温速度方面却很不一致。本文中,通过系列试验查明升温速度对软化点高低有显著影响,软化点愈高,偏差愈大。加热介质对所测软化点也有影响,甘油浴产生的软化点稍高于水浴获得的软化点。水浴用水应为新煮沸并冷却至5℃的蒸馏水,也可用饮用纯净水。应按(5±0 5℃)/min的加热速度来测定壳法酚醛树脂的软化点。更多还原

【Abstract】 The softening point is taken as the sign to differentiate the license tag of the novolac resins used for shell process in our country. Although the softening point is determined by the ringand瞓all method, the heating medium and the rate of heatingup are various. In this paper, It is found that the significant effect of the rate of heatingup on the softening point by a series of experiments. The more higher the softening point the more obvious the distinction. There is the effect of the heating medium on the determination of the softening point too. The softening point in the bath glycerin is the less higher than the softening point in the bath water. The water used in bath water should be the lately boiled and cooled down to 5℃’s distilled water, or be pure water for drinking. The rate of the heatingup should be (5±05℃)/min to determine the softening point of the novolac resins used for shell process.更多还原