Product Description
Introduction to Propylene Glycol
Propylene glycol, commonly referring to 1,2-propanediol and 1,3-propanediol, is a group of organic compounds with significant industrial, pharmaceutical, and consumer applications. Below is a detailed introduction to these compounds, with a primary focus on the more common 1,2-propanediol:
1. Basic Information
- Chemical Formula:
- 1,2-Propanediol: C3H8O2 or CH3CH(OH)CH2OH.
- 1,3-Propanediol: C3H8O2 or HOCH2CH2CH2OH.
- CAS Number:
- 1,2-Propanediol: 57-55-6.
- Physical Properties:
- Appearance: Colorless, odorless (or slightly sweet-smelling), viscous liquid at room temperature.
- Density: ~1.036 g/mL (25°C).
- Melting Point: -59°C (1,2-propanediol).
- Boiling Point: 188.2°C (1,2-propanediol).
- Solubility: Miscible with water, ethanol, and ether; stable under heat and light, especially at low temperatures.
2. Production Methods
- 1,2-Propanediol:
- Epoxy Propane Hydration: The dominant industrial method, involving hydrolysis of epoxy propane under high temperature (200-220°C) without a catalyst or with catalysts like ion-exchange resins, sulfuric acid, or bases (150-180°C).
- 1,3-Propanediol:
- Biotechnological Conversion: Utilizes genetically modified Escherichia coli to convert glucose into 1,3-propanediol, offering ~40% energy savings compared to traditional processes. Alternatively, it can be produced from glycerol (a biodiesel byproduct) via microbial fermentation (e.g., Clostridium diolis).
- Glycerol Conversion: Glycerol can also be processed to yield 1,2-propanediol, though the product often has residual odor/taste, limiting its use to industrial applications.
3. Applications
- Industrial Uses:
- A key raw material for synthesizing unsaturated polyesters, epoxy resins, and polyurethanes (accounting for ~45% of total consumption).
- Used in manufacturing surfactants, emulsifiers, and demulsifiers.
- Serves as an antifreeze and heat transfer medium in automotive coolants, aircraft de-icing fluids, and industrial processes.
- Food Industry:
- Approved as a food additive (e.g., in the EU under E1520 and in the US FDA as GRAS) for functions like humectant, stabilizer, emulsifier, and solvent for flavors/colors.
- Extends shelf life by retaining moisture in baked goods and acts as a carrier for food additives.
- Pharmaceuticals:
- Used in creams, lotions, and ointments as a solvent, softener, or excipient.
- Enhances stability and bioavailability of drugs in oral/topical formulations; serves as a carrier in medicinal capsules.
- Cosmetics and Personal Care:
- Widely used in skincare, haircare, and makeup products as a humectant (retains moisture), solvent, and texture enhancer.
- Improves product consistency and prevents drying in lotions, shampoos, and deodorants.
4. Safety and Regulations
- Toxicology:
- 1,2-Propanediol is generally regarded as safe (GRAS) for oral and topical use at regulated levels. The WHO suggests a tolerable daily intake (TDI) of ≤25 mg/kg body weight.
- Low concentrations are non-irritating to skin and may even have moisturizing effects. However, high concentrations can disrupt the skin barrier, causing dryness or irritation.
- Regulatory Standards:
- Food/Pharma: Complies with FDA (US), EFSA (EU), and China National Standards (GB 2760).
- Industrial: Must meet purity requirements for specific applications (e.g., low impurity levels in pharmaceutical grades).
5. Key Differences Between Isomers
Property |
1,2-Propanediol |
1,3-Propanediol |
Structure |
Two hydroxyl groups on adjacent carbons |
Hydroxyl groups on terminal carbons |
Production Scale |
Larger industrial production |
Primarily used in specialized applications |
Applications |
Widespread (food, pharma, industry) |
Niche uses (e.g., polymer synthesis) |
Toxicity |
Low (GRAS status) |
Generally low, but less studied |
Product Parameters
Packaging & Shipping
Liquid products |
Drum of 5kg ,10 kg ,25 kg ,50 kg 200 kg ,250 kg . 1000 kg IBC drum. TANK with 20 tons ,25 tons . |
Solid products |
Bag of 1 kg ,2 kg ,5 kg ,25 kg ,500kg ,1000 kg . Drum of 25 kg and 50 kg. |
Packaging can be customized according to customer requirements.
Company Profile
Qingdao Jinyu Chemical Co., LTD,which is located in Qingdao City, China, with registered capital of RMB 10 million, is a dynamic chemical import and export enterprise with customer demand as its own responsibility. The founder has been engaged in the chemical industry for more than 20 years. With professional technical and marketing personnel, diversified cooperative factories with synthetic technology and efficient logistics management, we provide services to customers all over the world. After years of hard work, we have selected a number of excellent chemical production cooperative enterprises in China. These enterprises have their own advantages in different chemical synthesis fields. They have passed the strict inspection of suppliers by many customers and formed a long-term and stable strategic partnership with customers. With our partners' excellent equipment, well-trained employees and mature technology, we also continue to provide customers with more products.



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