Since natural rubber is a thermoplastic, it will melt when heated and returns to solid when cooled to room temperature. Did anyway for it to remain as liquid even it is cooled to room temperature? A heating of 200 degree celsius is done to the rubber but it return to solid as well when it is cooled to room temperature.Any chemicals can be added to prevent the heated rubber from resolidify?
Natural rubber is an elastic polymer produced using sap obtained from a rubber tree. The sap is generally processed into either sap concentrated (latex) for manufacture of dipped products such as glove or it can be coagulated into skim block rubber. Natural rubber is a thermoset materials such that the molecular chains are cross-link together during the curing process to form an irreversible chemical bond and there is no available method to decrosslinked the cured natural rubber into liquid.
http://www.dprindustries.com/ but as we can see, there is some industry in oversea already started to sell liquid natural rubber.
Liquid natural rubber (LNR) with a molecular weight Mn =16×103 was prepared by the depolymerization of deproteinized natural rubber latex (DPNR). There are few available methods in the literature.LNR are prepare from latex and there is no available method to depolymerised solid rubbers into liquid. Hope this may help..
ok, I get what you meant, thanks. May I know is there any simple method to produce liquid natural rubber commercially? What I seen from journal is the latex added with catalyst and surfactant and heat it, the final step is to reprecipitate to purify it, this method is suitable for lab scale as it will be troublesome to do it commercially. My friend heats latex to 200 degree celsius to depolymerize it but it turns to solid when cooled to room temperature.Any reagents can be added to ensure that the depolymerized latex still in liquid?
Natural rubber can be depolymerized into natural rubber by using reduction and oxidation stage via latex route. However after the end of reaction the latex need to be coagulated for determination of molecular weight
NR is a thermoset and can only be used as a product of usefulness by vulcanizing it with sulfur or peroxide. Once it is cured it will not return to original state like a thermoform polymer. They call it a “one and done” for that reason. You can thermally degrade which cuts the long chain polymers by both mechanical and thermal processes and once it’s viscosity is significantly reduced it will no harden. We make liquid NR in our lab for use as an additive but the MW is greatly reminisced as are the physics properties and to date we have not cured the polymer to form a product or article as it is too weak. In such a state after degradation it will oxidize fast so an antioxidant is required. Protein levels will reduce as well and in the final cured product will be undetectable. This liquidity can be done on Epoxidized NR as well and is often more appropriate for compound blending as the polarity is further shifted. Good luck. J
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