Rubber monomers, condition for production of rubber, Vulcanization of rubber- physical chemistry
Rubber
Monomers
Important conjugated dienes used in synthetic rubbers include isoprene (2-methyl-1,3-butadiene), 1,3-butadiene, and chloroprene (2-chloro-1,3-butadiene).
Condition for the reaction leading to formation of rubber
- Synthetic elastomers are produced on an industrial scale in either solution or emulsion polymerization methods
- In solution polymerization, the monomer or monomers are dissolved in a hydrocarbon solvent, usually hexane or cyclohexane, and polymerized, using an organometallic catalyst such as butyllithium. Polymers made in solution generally have more linear molecules (that is, less branching of side chains from the main polymer chain), and they also have a narrower distribution of molecular weight (that is, greater length) and flow more easily. In addition, the placement of the monomer units in the polymer molecule can be controlled more precisely when polymerization is conducted in solution.
-
- In emulsion polymerization, the monomer (or monomers) is emulsified in water with a suitable soap (e.g., sodium stearate) employed as a surfactant, and a water-soluble free-radical catalyst (e.g., potassium persulfate, peroxides, a redox system) is added to induce polymerization. When emulsion polymerization of SBR is carried out “hot” (i.e., at 50 °C, or 120 °F), the polymer molecules are more branched. When polymerization is carried out “cold” (i.e., at 5 °C, or 40 °F), they are more linear and generally higher in molecular weight—features that improve the rolling resistance and wear resistance of tires. In some cases polymerization is continued in order to give products of such high molecular weight that they would normally be intractable. In these cases about 30 percent of a heavy is added before coagulation to yield “oil-extended” elastomers with superior wear resistance.
Vulcanization of rubber
This is heating rubber with sulphur
- to make more resistant to heat and cold,
- give it higher tensile strength and resistance to swelling and abrasion,
- increase its elasticity over a greater range of temperatures.
Sponsored by The Science Foundation College +256 753 80 27 09
Compiled by Dr. Bbosa Science + 256 778 633 682
CATEGORIES Organic chemistry
TAGS Dr. Bbosa Science
Your content is consistently great. Clothes & Accessories
Your content is always worth the read. Top adult movies
Simplify your enrollment with MBBS Admission Through Management/Nri Quota in Maharashtra.
Secure direct access to premier institutions with MBBS Direct Admission in Rajasthan.
Challenge yourself and win amazing prizes with the Raja Luck Game.
Gain practical knowledge about Raja Luck.
Navigate through intuitive interfaces and enjoy smooth gameplay on Goa Game, designed for optimal user satisfaction.
Increase your referral bonuses and rewards by inviting new users with your Invitation Code.
Want free perks? Redeem the Raja Luck Invite Code today and enjoy bonuses.
Get the best start with Raja Luck by redeeming the Raja Luck Invite Code.
Get High-quality backlinks and improve your website’s credibility and ranking.
Turn every video game into a chance to win big by using the Diu Win Invite Code.
Join thousands of gamers and use bdg-win for an unforgettable experience.
Sign up with millions of gamers worldwide on 55-club and experience the excitement of winning.
Explore the principle of What Is a Technology Roadmap and why it’s important for business growth.
Only MP3 is a vital tool for music lovers who want to listen offline.
82 lottery is great for casual and skilled gamers alike.
The Yamuna Expressway Authority Property Dealers here supply excellent service and offers.
Get the most recent updates on **IPL Teams Jersey**, featuring new styles and group colors for the upcoming season.
The creativity in every short on https://www.youtube.com/@kpopbuzzindo/shorts is truly impressive!