In many rubber recipes (for NR, SBR, ...), that contain peroxides as a vulcanization agent, there is used also zinc oxide. Do you know, what is the reason for that, when there is no sulfur?
Dear Drahomir Cadek, ZnO has different roles depending on the recipe and the curing system used. It may be a curing agent (alone), activation/accelerator, antibacterial additive, filler. Please check you mail box, I sent you a document. My Regards
Dear Abdelkader BOUAZIZ, thank you for your reply and also for the document. I look there and I find the same information like in other papers or books. I know, that ZnO is activator for sulphur vulcanization, it is used as a curing agent for CR for example, but I still don´t understand the role by peroxide vulcanization. Please look on page 29, where you can see three different recipes for EPDM. In all of them is ZnO. Carbon blacks are there, so ZnO as a filler? I don´t know. I here from people that works in industry, that it could be connected with some historical recipes, that are today not used, but some chemicals are still in recipes. Thank you one more time.
As I told you it has many benifits, but according to the following document, people already started to replace it for some environmental concern.
Dear Drahomir Cadek . Due to its texcellent properties:
1. it acts as an activator for the vulcanization of rubber.
2. Natural rubber is converted into a more durable material through a chemical process called vulcanization using ZnO.
3 Zinc Oxide adds strength to rubber compounds and improves their resistance against heat/abrasion.
4. ZnO helps guard against ultraviolet degradation.
5. The high use of zinc oxide in the rubber industry is due to so many optical, physical, and chemical properties it has.
See the link: https://www.citracakralogam.com/zinc-oxide-in-rubber-industry-formulations-manufacturing/
Kindly see also the following useful RG links: Article Enhancing the Performance of Rubber with Nano ZnO as Activators
https://patents.google.com/patent/US20030008937A1/en
https://www.tandfonline.com/doi/abs/10.1080/00222349808220461#:~:text=Mineral%20sulfur%20is%20a%20widely,and%20weak%20needles%20into%20pieces.
Yes, that is true, it is wonderful material used also in cosmetic. Enviromental problems is connected with negative influence on water life, we little bit study it in past. But, nobody knows, what will be the future, it TiO2 will be reduced or replaced in future, because there are also some risks. Then there is no other useful white pigment like ZnO. I have worked with ZnO and similar substances for more years and in almost every case we know, why we use some substance in recipe. But here, for me, it is still secret the usage of ZnO with peroxide cure system. Thank you.
Also check please the following useful RG links: https://pubs.acs.org/doi/pdf/10.1021/ie50451a023?rand=5epty1ac
https://science.howstuffworks.com/rubber2.htm
https://www.sciencedirect.com/topics/materials-science/vulcanization-agent
http://polymerdatabase.com/polymer%20chemistry/Vulcanization.html
For the usage of ZnO and peroxide see the following links: http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/32/016/32016532.pdf?r=1
https://www.slideshare.net/PankajDas19/vulcanization-mechanism-of-natural-rubber
Dear Aref Wazwaz,
thank you so much for very nice answer. Many of your points are connected with sulfur vulcanization. I think in peroxide vulcanization are lot of them impossible. There is no sulfur. But the possibility of some antidegradation role could be intersting.
- Badges
- Science topic