Organic Radical Polymer

High Polymer Labs Limited Company

Importance of Light Stabilisers

Polymers when exposed to sunlight are affected by the Ultra violet radiation. This radiation degrades the polymers. The photo oxidative process which degrades these polymers restricts the use of polymers in various fields. To protect them from the UV radiation the light stabilizers are used. The band of light which is responsible for degradation of the polymers ranges from 290 to 400 nanometer. This is the ultra violet zone of light. There are different ways through which the polymers are protected from these harmful ultra violet radiations. These are known as UV quencher, Radical scavenger and UV absorber.

The function of the UV absorber is to properly absorb the radiation. It is done in the presence of Chromophore in the polymer. Any absorber functions within 290 to 350 nanometer range. The absorber quickly absorbs the UV light and then quickly transforms it to harmless heat. During the process of conversion the energy which is absorbed is converted into rotational and vibrational energy. During such conversion neither the polymer nor the absorber are damaged. UV quenchers also act in similar method. They take the energy absorbed by Chromophore of the polymers and then quickly dispose the absorbed energy as heat. This lowers the light energy of fluorescent radiation. The Choromophores which absorbs the radiation energy can either remove hydrogen atom from polymers or can decompose and form radicals. This might lead to free radical reaction. For suppressing these reactions Radical scavengers are used for trapping the radicals. This interrupts the chain reaction.

Optical brighteners are type of agents that are used for absorbing ultra violet radiations. These types of additives are also used for enhancing the color of plastics, papers and fabrics. There are different types of Optical brighteners available in the market. Some of the important brighteners are HITEX-OB and HITEX-OB1. HITEX-OB is used in protecting and coloring the polyesters, polyamides, polycarbonates, copolymers, polyolefins, PVC, thermoplastics, acrylics and many other types of organic substances. HITEX-OB1 is considered as fluorescent whitening agent. It is used in polymer substrates like polyamide fibers and polyesters. It is also used in acrylics, polycarbonates, copolymers and polyolefins.
Light Stabilisers and Optical brighteners are manufactured by various companies. These companies use the best type of raw materials in manufacturing these compounds. The prices of these polymers are very reasonable and these are easily available in the market. One must always read the proper instruction for using and handling these compounds for better results.

Organic Chem Question For MCAT?

I am studying for my mcats right now. Im applying to medical school. Im taking a practice one, and im confused on this question.

D) would be the best preparation. Although the acetate group would inhibit the free radical polymerization to a degree it wouldn’t stop it entirely (being an electron withdrawing group), so you would probably have to react for a longer amount of time. The hydrolysis would be a snap, and the polymer would be easy to isolate by precipitating it into acetone. The excess base could then be rinsed out of the precipitated polymer with a 50/50 acetone/water mixture.

Free Radical Reactions

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