Heptamethyltrisiloxane

What is Heptamethyltrisiloxane and Why Its Molecular Weight Matters?​​

Heptamethyltrisiloxane, a silicone-based compound with the chemical formula ​C₇H₂₂O₂Si₃, is a critical intermediate in industrial and scientific applications. Its molecular weight of ​222.50 g/mol​ plays a pivotal role in determining its physical properties, reactivity, and suitability for specialized uses. Below, we delve into its molecular characteristics, applications, and why precise molecular weight data is essential for researchers and manufacturers alike.

​1. Molecular Composition and Weight​

Heptamethyltrisiloxane’s structure features three silicon atoms linked by oxygen bridges, with seven methyl groups attached. This arrangement gives it a molecular weight of ​222.50 g/mol, calculated from its constituent atoms:

• Carbon (C): 7 atoms × 12.01 = 84.07 g/mol
• Hydrogen (H): 22 atoms × 1.008 = 22.18 g/mol
• Oxygen (O): 2 atoms × 16.00 = 32.00 g/mol
• Silicon (Si): 3 atoms × 28.09 = 84.27 g/mol
  This composition ensures stability and compatibility with diverse chemical reactions, particularly in surfactant synthesis and polymer modifications .

​2. Key Properties Influenced by Molecular Weight​

The molecular weight directly impacts:

• ​Boiling Point: At 142°C (lit.), its moderate volatility suits applications requiring controlled evaporation, such as coatings and adhesives .
• ​Solubility: Insoluble in water but miscible with organic solvents like chloroform and ethanol, making it ideal for solvent-based formulations .
• ​Reactivity: The high silicon-hydrogen bond activity facilitates hydrosilylation reactions, enabling efficient synthesis of functionalized siloxanes for agrochemicals and pharmaceuticals .

​3. Applications Across Industries​

​A. Surfactants and Wetting Agents​

Heptamethyltrisiloxane is a precursor for ​polyether-modified siloxanes, which exhibit ultra-low surface tension (<20 mN/m). These “umbrella-shaped” molecules are pivotal in:

• ​Agriculture: Enhancing pesticide absorption by crops through superior wetting .
• ​Cosmetics: Improving spreadability and hydration in skincare products .

​B. Biomedical and Diagnostic Tools​

In tissue engineering, modified heptamethyltrisiloxanes act as biocompatible carriers for drug delivery, leveraging their inertness and stability .

​C. Industrial Additives​

As a silylating agent, it modifies polymers to improve thermal resistance and lubricity in coatings and lubricants .

​4. Quality Assurance and Supplier Considerations​

For applications demanding high purity (≥99%), suppliers like ​Biyuan Chemicals​ provide rigorously tested heptamethyltrisiloxane. Key certifications include:

• ​ISO 9001: Ensures consistent quality in pharmaceutical-grade batches.
• ​REACH Compliance: Confirms safety for use in EU-regulated products.
  Biyuan’s product range supports bulk orders (1kg to 20 tons), with customizable packaging for niche applications like lab-scale research .

​5. Safety and Handling Guidelines​

While generally stable, heptamethyltrisiloxane requires precautions:

• ​Flammability: Flashpoint at 52.8°C necessitates ventilation in storage.
• ​Toxicity: Classified as harmful if inhaled (H331) or irritating to skin (H315) .

​Conclusion​

Understanding the molecular weight of heptamethyltrisiloxane (222.50 g/mol) is foundational for optimizing its use in surfactants, biomedicine, and materials science. For industries prioritizing precision and compliance, partnering with trusted suppliers like ​Biyuan Chemicals​ ensures access to high-performance, certified materials tailored to evolving technical demands.

Need reliable heptamethyltrisiloxane for your next project? Explore Biyuan’s premium-grade offerings today!

Sources cited integrate peer-reviewed research and industry specifications to ensure accuracy. For detailed protocols or procurement inquiries, refer to the original studies and supplier listings .