1,16-Hexadecanediol

1,6-hexadecanediol has a wide range of uses and is useful in various fields. In the chemical industry, it is an essential material for the synthesis of special polyesters and polyethers. By condensation and polymerization of diols and diacids, polymer polymers with unique characteristics can be obtained. These polymers, in the genus of coatings and adhesives, can increase their toughness, wear resistance and chemical stability. The paint can be resistant to wind and rain erosion for a long time, and the adhesive is used to have stronger bonding force and lasting for a long time. In the field of medicine, 1,6-hexadecanediol also has a place. Because of its suitable physicochemical properties, it can be used as a raw material for drug sustained-release carriers. The prepared carrier can control the drug release rate, so that the drug is slowly released in the body, and the drug effect is exerted for a long time, and the instantaneous stimulation of the drug to the body is reduced. In the field of material science, it can be used to make special functional materials. If participating in the preparation of liquid crystal materials, it can help adjust the phase transition temperature and liquid crystal state properties of the material, so that the image of the liquid crystal display is clearer and more stable. In addition, its body shadow is also common in the daily chemical industry. It can be added to skin care products and cosmetics. With its moisturizing and moisturizing properties, it can keep the skin hydrated, improve the skin feel, and increase the product quality and experience. In summary, 1,6-cetanediol is an indispensable raw material in many fields such as chemical industry, medicine, materials, and daily chemicals, promoting the development and progress of various industries.

1,6-hexadecanediol has various physical properties. It is in a white crystalline state at room temperature, which is easy to see. Looking at its melting point, it is between 49 and 51 ° C, just like ice melts when it is warm. At this temperature, this substance gradually changes from solid to liquid, which is a sign of this phase transition. On its boiling point, it is about 338 ° C. Under the hot topic, it turns into a gaseous state, which shows its high thermal stability. Its density is about 0.845g/cm ³, which is lighter than water. If placed in water, it will float on the water surface. This is determined by the ratio of its mass to volume. Furthermore, 1,6-cetane diol is slightly soluble in water, just like oil drops into water, and it is difficult to miscible with water. However, in alcohols, ethers and other organic solvents, it has better solubility, like a fish in water, and can be fused with it. The difference in solubility comes from the difference between its molecular structure and the forces between water molecules and organic solvent molecules. And because of its long molecular chain, it has certain flexibility, and the hydroxyl groups at both ends endow it with a certain reactivity. It can play a unique role in many chemical reactions and material preparation, and is important for industry and scientific research.

The synthesis of 1,6-hexadecanediol follows the following methods. First, hexadecanediol and its esters are used as starting materials. First, hexadecanediol or its esters are reacted with suitable reducing agents, such as lithium aluminum hydride, at low temperature and in ether solvents, such as anhydrous ethyl ether or tetrahydrofuran. Lithium aluminum hydride is highly reducible and can reduce carboxyl groups or ester groups to alcohol hydroxyl groups. This process requires strict control of the reaction temperature and the amount of reagents to prevent excessive reduction. After the reaction, 1,6-hexadecanediol can be obtained through post-treatment steps such as hydrolysis, extraction, and distillation. Second, hexadecanediol can be obtained. The hexadecanhydride is reacted with alcohols, such as methanol or ethanol, under the action of a catalyst to form a hemiester. Then the hemiester is treated with sodium borohydride isothermally and a reducing agent, and the carbonyl group is reduced to a hydroxyl group. Compared with lithium aluminum hydride, sodium borohydride has slightly weaker reductivity, and the reaction is milder and easier to control. After subsequent separation and purification, the target product can also be obtained. Furthermore, hexadecyl halide is used as the raw material. 1,6-dihalohexadecane is first prepared, and then reacted with magnesium powder to form a Grignard reagent. Grignard reagent is extremely active and can react with ethylene oxide. After hydrolysis, two hydroxyl groups are successfully introduced to synthesize 1,6-hexadecanediol In this path, the preparation and reaction conditions of Grignard's reagent are quite high, and an anhydrous and anaerobic environment is required to prevent its failure. When synthesizing 1,6-hexadecanediol, each method has its own advantages and disadvantages. Using hexadecenedioic acid and its esters as raw materials, although the raw materials are easy to obtain, the use of lithium aluminum hydride is dangerous and the post-treatment is complicated; starting from hexadecanedioic anhydride, the reaction is mild but there are many steps; using hexadecanyl halide as raw material, although the carbon chain can be constructed and hydroxyl groups can be introduced, the preparation of Grignard's reagent is difficult. In actual synthesis, the method needs to be carefully selected according to factors such as raw material availability, cost, and equipment conditions.

For 1% 2C6-162ol, many matters need to be paid attention to during storage and transportation. Although its properties are relatively stable, when storing, it should be placed in a cool, dry and well-ventilated place. This may cause its properties to change if it is in a high temperature or humid place. High temperature can greatly increase the molecular activity of the product or cause chemical changes; moisture can easily cause it to absorb moisture and affect its purity. Furthermore, storage containers should also be selected with caution. Use those with good sealing performance to prevent excessive contact with air. When the alcohol encounters oxygen, it may react with oxidation, which will damage its quality. And the material of the container is also particular, and it should not react chemically with the 162ol to avoid contaminating the product. As for transportation, the first thing to do is to ensure that the packaging is intact. The road is bumpy. If the packaging is not solid, there may be a risk of leakage. Leakage not only wastes materials, pollutes the environment, but also endangers the safety of transporters. The means of transportation should also be clean and dry to avoid other impurities from mixing in. At the same time, open flames and hot topics should be avoided during transportation to prevent danger. Although the cover of 16 glycol is not extremely flammable, there are still potential safety hazards in the event of open flames and hot topics. In short, in the storage and transportation of 1% 2C6-16 glycol, caution is required everywhere to ensure its quality and safety.

There are many Quality Standards related to 1,6-hexadecanediol, which are related to its purity, appearance, melting point, moisture and color, etc., which are all key elements to measure quality. The first is purity, which is the core indicator. High purity 1,6-hexadecanediol has few impurities and can greatly improve product performance. It is widely used in high-end fields, such as medicine and cosmetics. The purity usually needs to reach more than 99% or even higher to meet strict requirements. Appearance is also important. Normally, it is white crystalline powder or flake solid, with uniform color and no visible foreign matter. If the appearance is abnormal, or it suggests that there is a quality problem, it will affect downstream applications. Melting point is a characteristic parameter. The melting point of 1,6-cetane diol is about 49-52 ° C. It deviates from this range, or due to insufficient purity or impurities, it affects the use. Moisture content is also critical. Excessive moisture may cause product performance deterioration. Especially for sensitive applications, moisture needs to be strictly controlled, generally not exceeding 0.5%, and specific field requirements are more stringent, close to zero moisture. There is also chromaticity, which reflects the purity and impurity content of the product. It is often expressed in APHA or Hazen units. Low-chromaticity products are more popular, usually lower than 50 APHA or Hazen units, to ensure product color and stability.