Epoxy resin is a commonly used polymer whose performance plays a key role in many industrial applications. The softening point is a key indicator of epoxy resin, which reflects the molecular weight and molecular weight distribution of Resin. This article will introduce a commonly used global method for determining the softening point of epoxy resin, including experimental steps and result representation.
The importance of softening points
The softening point is a key performance indicator of epoxy resin. It indicates the temperature at which the Resin changes from hard to soft and exhibits fluidity after heating. The softening point is usually expressed in degrees Celsius (℃). The low molecular weight Resin softening point is lower, while the high molecular weight Resin softening point is higher. The softening point is one of the important factors affecting the performance of epoxy resin and its application.
Determination of softening point
The softening point is determined using a standardized procedure called the globe method, which is applicable to different types of epoxy resins.
1. Resin with softening point below 85 ℃
Prepare a beaker with freshly boiled distillation water and chill down the water temperature to below 45 ℃ below the estimated softening point.
Load the Resin sample into a copper ring and then place the copper ring on the Stirrer bracket.
Place a steel ball in the water and place it in the center of the copper ring with forceps.
Insert the thermometer into the center hole of the bracket.
Start Stirrer and start testing.
With a heater heating beaker, heat up at a rate of 5 ℃ per minute until Resin softens and the ball falls to the baseplate, at which time the temperature indicated by the thermometer is the softening point.
2. Resin with softening point higher than 85 ℃
Use a similar procedure as above, but use a glycerin bath instead of water. The glycerin needs to be preheated to below 45 ℃ below the estimated softening point, but not below 32 ℃.
Result representation
The softening point test results shall be expressed as the arithmetic mean of the measured values of the two parallel samples, reserved to one decimal place. The difference between the two measured values of the parallel test shall not exceed 0.5 ℃.
Reference standard
In order to ensure the accuracy of the softening point, you can refer to the national standard GB 12007.6-89 "Determination method of epoxy resin softening point" and the international standard ISO 4625-80 "Coating and varnishes binder softening point determination global method".
Conclusion
The softening point is an important performance indicator of epoxy resins, which reflects the molecular weight and molecular weight distribution of Resin. Accurate evaluation of epoxy resin performance can be ensured by using a global method to determine the softening point. This method can be applied to various types of epoxy resins, providing reliable performance data for applications such as Coating and Adhesive. Epoxy resin manufacturers and researchers should follow standard procedures to ensure that the performance of their products meets requirements.
