Polypropylene glycol PPG-200, a low molecular weight (190~210) polyether polyol produced by Guoli Chemical, stands out with its competitive advantages across multiple dimensions. Compared to similar products with higher molecular weights, such as PPG-400, PPG-600, and PPG-1000, PPG-200 features a hydroxyl value as high as 540~590 mgKOH/g, indicating a much higher density of active hydroxyl groups at the ends of its molecular chains. This property enables faster and more thorough crosslinking reactions with isocyanates when used as a starter in flexible polyurethane foam, resulting in finer cell structures and improved rebound comfort in the final foam products. Additionally, as an intermediate for synthesizing nonionic surfactants, its high hydroxyl value provides abundant reaction sites for subsequent chemical modifications such as etherification and esterification, offering far greater flexibility in molecular design compared to higher molecular weight counterparts.
Another significant advantage is PPG-200's excellent low-foaming performance and its strong affinity for water-based systems. Unlike medium- and high-molecular-weight counterparts that may cause gelation or turbidity in certain aqueous applications due to increased hydrophobicity (lower cloud point), PPG-200 is clearly water-soluble and has a low surface tension of 31~33 mN/m. It can quickly spread and exert wetting and penetrating effects in aqueous phases without the need for additional cosolvents. Combined with its inherently low foaming nature, this product serves as a core raw material for preparing efficient and long-lasting defoamers in industries such as fermentation, papermaking, and coatings, effectively avoiding secondary foam issues associated with traditional high-foaming surfactants—a unique advantage among similar products.
In terms of safety and processability, PPG-200 also excels. Its flash point exceeds 200°C, far higher than many low-viscosity organic solvents and some similar products (such as certain polyethylene glycol series) on the market, providing intrinsically safe processing characteristics in high-temperature lubricants, hydraulic fluids, and high-temperature mold release processes. Meanwhile, its acute oral toxicity LD50 is greater than 2000 mg/kg, classifying it as low-toxic and non-hazardous. Its mild skin and eye irritation properties allow it to be used as a safe humectant and emollient intermediate in daily cosmetic formulations. This "dual applicability in industry and daily chemicals" green attribute is a core advantage that high-polymerization-degree similar products can hardly match.
| Key Indicator | PPG-200 (Guoli Chemical) | Reference Trend for Similar Products (PPG-400/600/1000) | Advantage Analysis |
|---|---|---|---|
| Average Molecular Weight | 190~210 | 400→600→1000 (increasing) | Lowest molecular weight, highest reactivity |
| Hydroxyl Value (mgKOH/g) | 540~590 | 280→190→112 (decreasing) | Highest hydroxyl value, providing more reaction sites |
| Kinematic Viscosity (40°C, mm²/s) | 30~40 | Significantly increases with molecular weight | Lowest viscosity, easier handling, better permeability |
| Surface Tension (mN/m) | 31~33 | Generally increases with molecular weight | High surface activity, strong wetting and spreading ability |
| Water Solubility | Soluble in water | Increased hydrophobicity with higher molecular weight, prone to phase separation | Best compatibility with water-based systems, fewer formulation constraints |
| Foaming Characteristics | Low foaming | Some varieties have higher foam or require defoamers | Naturally low foaming, suitable as core component for defoamers |
| Flash Point (°C) | ≥200 | Most above 100, but PPG-200 stands out | Outstanding safety in high-temperature processing |
Flexible Polyurethane Foam: As a starting polyol, it is recommended to use it in combination with high molecular weight polyether polyols (PPG-200 can account for 5% to 15% of the total polyol content). Its high hydroxyl value helps adjust the crosslinking density of the system, thereby precisely controlling foam hardness and rebound. This is a precise regulation method that cannot be achieved by using high molecular weight polyols alone.
Defoamer and Lubricant Manufacturing: In high-temperature chain oils or metalworking fluids, a recommended addition amount is 5% to 20%, leveraging its excellent viscosity-temperature performance and low surface tension to enhance lubricating film strength. As a defoamer carrier, it is recommended to compound with hydrophobic silica and other components; its low viscosity and high spreading performance can synergistically enhance defoaming speed.
Surfactant Synthesis: Taking advantage of its adjustable hydrophilic-lipophilic balance, hydrophilic groups such as ethylene oxide (EO) can be introduced through block copolymerization to synthesize low-foaming nonionic surfactants with precise HLB values, especially suitable for green formulations requiring rapid biodegradability and low aquatic toxicity.