Polypropylene Glycol PPG-400 (CAS: 25322-69-4) is a nonionic high-molecular-weight polymer synthesized through catalytic polymerization of propylene oxide and propylene glycol. It has an average molecular weight of approximately 380–420 and appears as a colorless to slightly yellow transparent viscous liquid. Its molecular structure contains abundant ether bonds and terminal hydroxyl groups, with an HLB value of about 2.0. It exhibits excellent chemical stability and is resistant to hydrolysis or decomposition in acidic, alkaline, and hard water media.
The core functional advantages of this product lie in four aspects: first, outstanding surface activity, effectively reducing interfacial tension for emulsification, wetting, dispersion, and solubilization; second, excellent reactivity, with high primary hydroxyl content suitable as a quality raw material for synthesizing polyurethanes, ester derivatives, and other products; third, good lubrication and moisturizing capabilities, with stable viscosity-temperature characteristics providing sustained lubrication across a wide temperature range; fourth, significant safety and mildness, with low acute oral toxicity (rat LD₅₀ > 2000 mg/kg), non-irritating to skin, non-sensitizing, meeting strict safety requirements for personal care and pharmaceutical applications.
Guoli Chemical uses clean and dry galvanized iron drums, plastic drums, or IBC totes for packaging, with specifications of 50 kg, 200 kg, and tote drums to meet the needs of customers of various scales. Under sealed original containers and recommended storage temperatures of 0–40°C, the shelf life is no less than 12 months.
In the PU industry, PPG-400 is a key soft segment component in flexible and rigid polyurethane foams, elastomers, coatings, and adhesives. Its core role is to regulate chain flexibility and hydrophilic-hydrophobic balance, imparting excellent flexibility, hydrolysis resistance, and low-temperature elasticity to final products. When reacting with isocyanates (e.g., MDI, TDI), the primary hydroxyl groups of PPG-400 effectively participate in chain extension and crosslinking reactions, making it an indispensable polyol raw material in high-end polyurethane product formulations.
PPG-400 can be directly used as a base oil or co-solvent component for synthetic high-temperature lubricants, hydraulic fluids, and compressor oils. Benefiting from its excellent viscosity-temperature characteristics (kinematic viscosity at 40°C of about 70 mm²/s) and high flash point (closed cup approximately 220–230°C), it maintains stable lubricating film strength under high-temperature conditions, while also offering good detergency and synergistic effects with antioxidants. It is widely used in metalworking fluids, industrial gear oils, and specialized hydraulic transmission systems.
As an intermediate for nonionic surfactants, PPG-400 is extensively used in industrial cleaning, textile auxiliaries, and pesticide emulsification. Its cloud point is approximately 50°C (1% aqueous solution), and it is readily soluble in water, alcohols, esters, and ketone solvents. It can be further processed via ethoxylation or converted into anionic derivatives such as phosphate esters and sulfates to expand its dispersion and emulsification performance in different media.
In creams, lotions, facial cleansers, and color cosmetics formulations, PPG-400 acts as a humectant, lubricant, and emollient, significantly improving skin feel, reducing stickiness, and aiding in the uniform dispersion of active ingredients. Its low irritation and low sensitization characteristics make it suitable for baby care products and products for sensitive skin.
With good biocompatibility and safety, PPG-400 is primarily used in the pharmaceutical field as a suppository base, ointment base, and drug solubilizer. It can serve as a consistency modifier to adjust the spreadability and extensibility of ointments while also acting as a plasticizer to enhance formulation stability.
Additionally, PPG-400 can be used as a core raw material for defoamers and mold release agents (especially in polyurethane molding processes), as a base component for heat transfer fluids, and as a nonionic lubricating component in synthetic fiber oils and textile spinning oils. Its low foaming properties and good chemical stability also make it perform excellently in demanding applications such as metal cutting fluids and quenchants.
| Parameter Name | Specification | Description |
|---|---|---|
| Appearance | Colorless to slightly yellow transparent viscous liquid | Visual inspection |
| Molecular Weight | 380~420 | Average molecular weight |
| Hydroxyl Value (mg KOH/g) | 260~300 | Reflects terminal hydroxyl content |
| HLB Value | Approx. 2.0 | Hydrophilic-lipophilic balance |
| Cloud Point (1% aqueous solution) | Approx. 50°C | Inversion temperature point |
| Kinematic Viscosity (40°C) | Approx. 70 mm²/s | Characterizes fluidity |
| Density (25°C) | 1.004~1.010 g/cm³ | — |
| Refractive Index (25°C) | 1.450~1.452 | — |
| pH Value (1% aqueous solution) | 6.0~8.0 | Near neutral |
| Flash Point (Closed Cup) | ≥200°C (approx. 220~230°C) | High flash point, good safety |
| Moisture Content | ≤0.1% | Low moisture |
| Acid Value (mg KOH/g) | ≤0.1 | Low acidity |
| Heavy Metals | ≤10 mg/kg | Meets safety requirements |
| Arsenic | ≤2 mg/kg | Meets safety requirements |