Analysis of gas emission and decomposition rate of blowing agent
The gas volume of blowing agent refers to the volume of gas released by the complete decomposition of blowing agent per unit mass in a standard state, and the unit is mL/g.
The decomposition rate of blowing agent refers to the amount of gas released by unit time decomposition of blowing agent of a certain mass at a certain temperature.
Since the polymer itself does not change the decomposition mechanism of the blowing agent, it is not possible to measure the amount of blowing agent in the polymer. Usually, the blowing agent is put into an inert dispersant (such as DOP or mineral oil) at a certain temperature, heated for a period of time to collect the released gas, plot the gas volume (converted to the volume under standard conditions) with the heating time of the decomposition of the blowing agent, the total volume of the decomposed gas after the complete decomposition divided by the quality of the blowing agent to obtain the blowing agent gas.
The decomposition rate of blowing agent is different with different varieties, particle size and temperature. Under normal circumstances, the foaming agent with low decomposition temperature has a fast decomposition speed. For the same blowing agent, the particle size is small, the temperature is high, and the decomposition speed is fast. The gas volume and decomposition rate of blowing agent affect the size and structure of the bubble hole, the gas volume is large, the decomposition rate is fast, the formation of the bubble hole is large, and the probability of opening the hole is large. Analysis of matching between decomposition rate of blowing agent and vulcanization rate of rubber compound.
The matching between them affects the formation and structure of the pores. If the decomposition rate of the foaming agent or the vulcanization rate of the rubber material is too large to match, it cannot be foamed. In order to achieve the matching of the two and make better rubber products, the choice of foaming agent and vulcanization system of rubber material is the key.
