Propylene Glycol

 

Propylene glycol is an organic compound with the chemical formula C3H8O2, classified as a diol, and due to its multifunctional properties, it has widespread applications in various industries including food, pharmaceutical, cosmetic, and industrial sectors. This substance is a colorless, odorless liquid with a slightly sweet taste, possessing medium viscosity. Due to its moisturizing properties, high solubility, and safety for human consumption, it has become one of the key raw materials in the production of everyday products. Propylene glycol is used as a solvent, humectant, emulsifier, and antifreeze agent in various formulations, and its ability to absorb moisture from the environment makes it ideal for applications requiring moisture retention. Unlike ethylene glycol, which is toxic, propylene glycol is non-toxic and has been approved in global standards such as the United States Pharmacopeia (USP) for use in food and pharmaceutical products. Due to its chemical stability, resistance to oxidation, and ability to interact with various substances, it plays an important role in industrial and commercial processes. Propylene glycol is produced in various grades including industrial and food-grade, each designed for specific applications. Because of its flexibility and safety, it is used in many products that come into contact with the human body or are used in sensitive environments.

 

Physical and Chemical Properties of Propylene Glycol

 

Propylene glycol is a clear liquid with a density of approximately 1.04 grams per cubic centimeter, which freezes at -59°C and boils at 188°C. Due to its hygroscopic property or moisture-absorbing capability, it can absorb water from the environment, making it a strong humectant in cosmetic and food products. Propylene glycol easily dissolves in water, alcohol, and many organic solvents but has limited solubility in nonpolar solvents such as hydrocarbons. Chemically, due to the presence of two hydroxyl groups, it has moderate reactivity and can participate in esterification reactions or serve as a solvent in chemical processes. Propylene glycol is resistant to oxidation and chemical degradation and remains stable under normal conditions, making it suitable for use in various environments. It is non-toxic and considered safe for human consumption in specified doses, which has led to its widespread use in food and pharmaceutical products. Its medium viscosity and antifreeze properties make it ideal for industrial applications such as cooling and heating systems. This substance also remains stable against pH changes and maintains its quality in production processes that require specific conditions.

 

Chemical Structure of Propylene Glycol

 

Propylene glycol, scientifically known as 1,2-propanediol, consists of a three-carbon chain with two hydroxyl (-OH) groups attached to the first and second carbons. Its chemical structure is CH3-CH(OH)-CH2OH. This structure makes propylene glycol a diol that, due to the presence of hydroxyl groups, is polar and interacts well with polar molecules such as water and alcohol. The methyl group (CH3) in its structure chemically differentiates propylene glycol from other diols like ethylene glycol and gives it non-toxic properties. This structure also enables propylene glycol to dissolve various substances and form stable emulsions, which are highly valuable in industrial, food, and cosmetic applications. The hydroxyl groups in the structure allow hydrogen bond formation, contributing to the substance’s high solubility and moisturizing properties.

 

Production Method of Propylene Glycol

 

Propylene glycol is primarily produced through the hydration process of propylene oxide. In this method, propylene oxide, which is derived from the oxidation of propylene (a petrochemical product), reacts with water in the presence of acidic or basic catalysts under high temperature and pressure to produce propylene glycol. This process includes purification steps such as distillation and filtration to obtain a high-purity final product. The produced propylene glycol can be offered in industrial or food grades, with food-grade requiring more precise purification steps to meet USP or food standards. Alternative production methods include the use of biological sources such as glycerol (a byproduct of biodiesel production), which is converted to propylene glycol through hydrogenation processes. These biological methods are under development due to their environmental sustainability, but due to higher costs, they are still less common at the industrial scale. The production process of propylene glycol is widely carried out globally due to the availability of petrochemical raw materials and high efficiency. Modern production technologies also help reduce energy consumption and improve product quality.

 

Applications of Propylene Glycol

 

Due to its multifunctional properties such as high solubility, moisturizing capability, and safety, propylene glycol has wide applications in various industries. This substance is used as a solvent, humectant, emulsifier, and antifreeze agent in diverse formulations and plays a major role in improving the quality and performance of products.

 

Application of Propylene Glycol in Industry

 

In the industrial sector, propylene glycol is used as an antifreeze agent in cooling and heating systems such as HVAC systems, industrial coolers, and automotive cooling systems. Due to its low freezing point and non-toxicity, it is a safer alternative to ethylene glycol in applications where environmental and human safety is important. Propylene glycol is also used in the production of plastics, polyester resins, and polyurethanes as a raw material or solvent. It is employed as a solvent for various reactions in chemical processes, and due to its chemical stability, plays a role in the production of industrial chemicals such as adhesives and coatings. The moisturizing property of propylene glycol is also utilized in the production of printing inks, lubricants, and hydraulic fluids, enhancing the performance and durability of these products. This substance is also used in the aerospace industry as an antifreeze agent in aircraft deicing fluids.

 

Application of Propylene Glycol in the Food Industry

 

In the food industry, propylene glycol is recognized as a safe additive with the code E1520 and is used as a humectant, solvent, and preservative in products such as cakes, cookies, ice cream, beverages, sauces, and dairy products. This substance helps retain moisture in food products and prevents them from drying out or crystallizing. Propylene glycol is also used as a solvent for flavorings and food colorings and contributes to creating a uniform texture in products like desserts and chocolates. Due to its non-toxicity and global food safety certifications, it is used in many food products to improve their shelf life and quality. Propylene glycol is also used in the production of gum and candy to create a soft and long-lasting texture. It acts as a stabilizer in carbonated beverages and dairy products, preventing the separation of water and fat phases.

 

Application in Hygiene Products and Detergents

 

In the cosmetic and hygiene industries, propylene glycol is used as a humectant, solvent, and stabilizing agent in the production of moisturizing creams, lotions, shampoos, liquid soaps, deodorants, and skin and hair care products. This substance helps retain moisture in the skin and hair and prevents cosmetic products from drying out over time. Propylene glycol is used in detergent formulations such as dishwashing and laundry liquids to adjust product viscosity and facilitate the even distribution of active ingredients. Its high solubility makes it ideal for creating stable emulsions in cosmetic and cleaning products. This substance is also used in the production of hand sanitizers as a moisturizing agent to prevent skin dryness from frequent use. Due to its odorless nature and skin compatibility, it is also used in sensitive formulations such as baby skin care products.

 

Pharmaceutical Industry

 

In the pharmaceutical industry, propylene glycol is used as a solvent, humectant, and stabilizing agent in the production of liquid medications, syrups, soft gel capsules, creams, and ointments. It helps improve the dissolution of active pharmaceutical ingredients and masks the bitterness of medications. Propylene glycol is used in topical products such as anti-inflammatory creams, medicinal moisturizers, and therapeutic ointments to enhance drug absorption through the skin. This substance is also used as a solvent in the production of vaccines and injectable solutions, and due to its high safety, it is suitable for pharmaceutical applications involving contact with the human body. Propylene glycol is also used in the production of suppositories to create a soft and stable texture. Due to its chemical stability, it maintains quality in sterile pharmaceutical production processes.

 

Propylene Glycol in Paints and Resins

 

In the paint and resin industry, propylene glycol is used as a solvent and viscosity regulator in the production of water-based paints, alkyd resins, and polyurethanes. It helps improve paint dispersion and achieve uniform coatings while preventing premature drying during production and application. Propylene glycol acts as a raw material in the production of polyester and polyurethane resins, enhancing the flexibility and durability of coatings. It is also used in the production of protective coatings and adhesives to improve the mechanical and chemical properties of the final product. The moisturizing property of propylene glycol in paint formulations helps preserve product quality under various environmental conditions.

 

Propylene Glycol in Perfume

 

In the perfume and cologne industry, propylene glycol is used as a solvent for essential oils and aromatic compounds. It aids in the even distribution of fragrances in perfume formulations, allowing the scent to disperse evenly on skin or clothing. Propylene glycol also helps increase the longevity of perfumes by preventing the rapid evaporation of aromatic substances. Due to its odorless nature, it does not affect the main scent of the perfume and is therefore highly favored in fragrance formulations. It is also used in the production of air freshener sprays and home fragrance products to enhance fragrance diffusion.

 

Antibacterial Property of Propylene Glycol Vapor

 

The vapor of propylene glycol, due to its antibacterial and antiviral properties, is used in some applications as a disinfectant agent. Studies have shown that the vapor of this substance can inactivate airborne bacteria and viruses, making it useful in ventilation and air purification systems, especially in hospital environments and public spaces. This antimicrobial property helps reduce the transmission of respiratory diseases, and due to its non-toxicity, propylene glycol vapor is safe for use in environments where people are present. This feature is also used in the production of artificial fog for theater and filmmaking, as the vapor of propylene glycol is harmless and non-irritating.

 

Persia Kamandar Paytakht Company – Importer of Propylene Glycol

 

 

Persia Kamandar Paytakht Company is one of the reputable importers of propylene glycol in Iran, offering this substance in high quality and in both food and industrial grades. This company supplies propylene glycol from reputable global manufacturers, delivering products that meet international standards such as USP and food-grade certifications. Persia Kamandar Paytakht provides professional consulting and support services to help customers select the product best suited to their specific needs. Guaranteed quality, competitive pricing, and customer-oriented services make this company a reliable choice for purchasing high-purity propylene glycol for food, pharmaceutical, cosmetic, or industrial applications. To obtain high-purity propylene glycol, you can contact the sales team of this company and benefit from their professional services.