Synthesis and application of similar quaternized chitosan sunscreen

Abstract

The invention relates to a synthesis method of similar quaternized chitosan sunscreen and an application of the quaternized chitosan sunscreen as hair sunscreen, belonging to the technical field of functional cosmetic. The product in the invention is obtained through the following two reaction steps: first step, 2-hydroxypropyltrimethyl ammonium chloride chitosan is synthesized from 3-chloro-2-hydroypropyltrimethyl amino and chitosan under alkali condition; second step, 2-hydroxypropyltrimethyl ammonium chloride chitosan is dissolved in dimethyl sulfoxide, and acyl chloride (sulfonyl chloride) and bind acid agent triethylamine are added in the solution to synthesize the final product quaternized chitosan sunscreen. Wherein, the acyl chloride (sulfonyl chloride) group grafted in the second step has quite strong ultraviolet absorption performance; besides, grafting quaternary ammonium group on the chitosan not only improves the water solubility of the chitosan and enlarges the application scope, but also enables the product to adhere to hairs with negative electricity. Measurement of tryptophan content in hairs proves that the product has sun-screening effect for hairs to some extent.

Description

Technical field [0001] The invention relates to the synthesis and application of a type of quaternized chitosan sunscreen, in particular to the preparation of a chitosan derivative which can be adsorbed on the hair and has the effect of absorbing ultraviolet rays and a preparation method thereof, belonging to the technical field of functional cosmetics. Background technique [0002] The factors that damage hair are generally divided into three categories: mechanical factors; chemical factors; environmental factors. Ultraviolet rays are considered the most harmful of all environmental factors. When hair is exposed to ultraviolet radiation, melanin will fade due to oxidation. In addition, sunlight radiation will also cause photodegradation of cystine, tyrosine, tryptophan and other groups in keratin, which will break the link between amino acids. , The basic structure of the hair is destroyed, the hair becomes dry, fragile, dull, and poor combability. [0003] Currently, few sunscr...

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Problems solved by technology

[0004] People have realized the importance of sun protection for hair, but the development of sunscreens for hair needs to solve the following problems: (1) Most of the sunscreens currently used are skin sunscreens, which have poor affinity and film-forming properties for hair. It is not easy to form a uniform protective film; (2) it must have a large solubility in water; (3) it will not produce a sticky feeling; (4) it will not affect the luster of the hair when it is adsorbed on the hair surface; (5) it is good for the scalp no irritation

However, chitosan itself has poor solubility and can only be dissolved in dilute acid, so its application is greatly limited.

[0006] 2-Hydroxypropyltrimethylammonium chitosan has good water solubility, but there are few products that further modify it

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