1. Chemical Structure and Properties
Molecular Formula: C₇H₁₆O₃
Structural Formula:
CH₃O-(CH₂CH(CH₃)O)₂H
A branched glycol ether composed of two propylene oxide units linked to a methyl ether group.
Physical Properties:
Appearance: Clear, colorless liquid with a mild ether-like odor.
Boiling Point: 190–195°C; Density: 0.95–0.97 g/cm³; Vapor Pressure:<0.1 mmHg at 25°C.
Solubility: Partially miscible with water (5% w/w at 25°C); fully miscible with alcohols, esters, and hydrocarbons.
Chemical Properties:
Hydrolysis Stability: Resistant to hydrolysis under neutral and mildly acidic/alkaline conditions.
Thermal Stability: Stable up to 200°C; decomposes above 250°C, releasing aldehydes and propylene oxide derivatives.
Flammability: Combustible (flash point: ~75°C).
2. Industrial Applications
Coatings & Inks:
High-Boiling Solvent: Enhances flow, leveling, and gloss retention in automotive and industrial coatings (e.g., epoxy, polyurethane).
Coalescing Agent: Improves film formation in waterborne latex paints.
Cleaning Products:
Precision Degreaser: Removes oils, greases, and waxes in aerospace, electronics, and medical device manufacturing.
Electronics:
Photoresist Developer: Cleans residues in semiconductor lithography processes.
Personal Care:
Emollient & Stabilizer: Used in cosmetics and lotions for its low volatility and skin compatibility.
3. Safety and Toxicology
Health Hazards:
Acute Exposure:
Skin Contact: Mild irritation (rabbit skin LD₅₀: >2,000 mg/kg); prolonged exposure may cause defatting.
Inhalation: Low volatility minimizes risk (TLV-TWA: Not established; handle as nuisance vapor).
Ingestion: Low toxicity (oral LD₅₀ rat: >5,000 mg/kg); gastrointestinal discomfort.
Chronic Effects:
Reproductive Toxicity: No teratogenicity observed in OECD 414 studies.
Organ Toxicity: Negligible hepatotoxicity or nephrotoxicity in subchronic rodent studies.
Protection Measures:
PPE: Nitrile gloves, safety goggles, and general ventilation.
Storage: Stable in HDPE containers; store away from strong oxidizers.
4. Environmental and Regulatory Compliance
Environmental Impact:
Biodegradability: Slow (OECD 301F:<30% in 28 days); moderately persistent in soil and water.
Aquatic Toxicity: LC₅₀ (fish, 96h): >100 mg/L; EC₅₀ (daphnia): >50 mg/L.
Bioaccumulation: Low (log Kow: ~0.9).
Regulatory Frameworks:
EU:
REACH: Registered with no SVHC listing; CLP classification Not Hazardous.
USA:
EPA: Exempt from VOC status under 40 CFR 51.100(s)(1); TSCA-listed.
China:
GB 13690-2009: Classified as General Chemical (non-hazardous).
Waste Management:
Incinerate in approved facilities; landfill disposal permitted for small quantities.
5. Case Studies and Application Insights
Case 1: Sustainable Automotive Paints (Axalta, 2023):
Challenge: Reduce VOC emissions in solvent-borne automotive primers.
Solution: Dipropylene glycol methyl ether replaced 20% of toluene.
Result: Achieved 30% lower VOC emissions (ASTM D6886) and maintained drying time (ASTM D5895).
Case 2: Green Electronics Cleaning (TSMC, 2022):
Process: Adopted dipropylene glycol methyl ether in 3nm-node photoresist stripping.
Impact: Reduced solvent waste by 25% and met EU RoHS compliance.
Comparative Analysis:
Dipropylene Glycol Methyl Ether vs. Ethylene Glycol Monobutyl Ether (EGBE):
Pros: Lower toxicity, higher boiling point, and better compatibility with hydrophobic substrates.
Cons: Higher viscosity (~15 mPa·s vs. 3 mPa·s) limits use in low-viscosity applications.
Dipropylene Glycol Methyl Ether vs. Propylene Glycol Methyl Ether (PGME):
Pros: Improved solvency for resins and reduced skin absorption risks.
Cons: PGME offers faster evaporation for quick-drying formulations.
Specifications：
Dipropylene Glycol Methyl Ether is a clear, low-odor solvent with excellent solvency, widely used in coatings, cleaning products, and chemical formulations, available in bulk from China Amines Co.