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Disproportionated rosin

i'm working in the production of polybutadiene. the emulsifier system that i'm using is based on disproportionated rosin. currently i was evaluating two supplier (A and B) of disproportionated rosin in polybutadiene polymerization. While using one the disproportionated rosin (from supplier A), PBD polymerization time increased compared to the other.

therefore, i checked the abietic acid level in both the rosin and there was no presence of abietic acid in both the rosins.

besides, abietic acid, what are the other chemicals in the rosin that can effect the polymerization process of PBD ?

can the source of the rosin (different species of tree) can it effect the polymerization process ?

i'm now checking for the acid value in the rosin product ? could it also affect the polymerization process ?

please reply me as it would help me in my research work

thank you very much.

Reply to
HARI
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What is being done by A and B to neutralize the acid? It's most likely an esterification, but with what? Do A and B have the same/similar R & BSP? If they are different, then the number of molecules will be different even at the same wt% of loading.

John Aspen Research, -

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Reply to
john.spevacek

I did a fair bit of research with different rosin sources for styene butadiene polymerization. Historically the SBR business used wood rosin which was extracted out of tree stumps. They then moved to gum rosin which was extracted from the sap of the living tree. More recently tall oil rosin has become the norm. tall oil rosin comes as a byproduct from the pulp milling process. I found that as long as they were disproportionated properly , and the amount of abietic acid is a good indication, then they all gave similar ( within say 5% ) reaction rates. there will be differences though due to difference in the different species. An important factor is getting the pH of the soap the same which may require different levels of caustic or KOH to achieve. terry

Reply to
d&tm

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