What are the characteristics of vulcanizing agent BIBP?

Vulcanizing agent BIBP belongs to peroxide cross-linking agent. It carries out free radical cross-linking during vulcanization, and has high cross-linking density for rubber products. During cross-linking, it does not emit irritating odor and does not pollute the environment. Suitable vulcanization methods are: molding vulcanization, autoclave vulcanization, high temperature continuous vulcanization.

The reason why BIPB is called tasteless DCP is not only the similar in structure, but also the important reason is that it can be replaced almost where DCP can be used. The rubber properties of BIPB replacing DCP, including hardness, breaking strength, elongation, tear strength, oil resistance and aging coefficient, are basically the same, while the compression deformation under high temperature, BIPB is better than DCP.

But BIPB has a significant disadvantage, that is, the price is too much higher than DCP, which is the biggest factor limiting the wide use of BIPB. The use of BIPB in Europe is much higher than that in DCP. With the strengthening of environmental awareness of domestic producers and consumers, the demand for BIPB in China is increasing.

Another major disadvantage of BIPB is that when BIPB is used as the crosslinking agent of EPDM, it is easy to spray crystal (note that it is spray crystal, not frost). It will be shiny when exposed to light, but DCP will not. This is due to the poor compatibility between the decomposition products of BIPB and EPDM. If your products are exported to foreign countries, especially in Europe, you can rest assured that customers will know that you are using a good curing agent and gladly accept it. If you want to solve this spray crystal phenomenon, there are two main methods:

1. Add PEG4000 into the formula;

2. Reducing the amount of BIPB and adding part of bis (2,5) is equivalent to reducing the decomposition products of BIPB without affecting the crosslinking efficiency.

There are successful examples of these two schemes. Of course, some manufacturers use BIPB as cross-linking agent for EPDM without crystal spraying, perhaps because some of the additives restrict the crystal spraying. The specific reason is unknown.

Thermoplastic rubber TPV also uses BIPB as the crosslinking agent, but with the increasing requirements of the automotive industry for odor, that is, after using BIPB, the odor may not meet the requirements, and further treatment is needed, such as chemical/physical adsorption, devolatilization, drying and other processes to reduce the odor.