Physical and chemical properties of dioctyltin dimercaptoacetate
Dibutyltin bis(isooctylthioglycolate), whose chemical formula is generally abbreviated as DBT-DOTG, is an organic tin compound that is widely used Stabilizer used in polyvinyl chloride (PVC) plastics, especially for the processing of transparent products, has a significant effect. It enables PVC products to maintain their physical and mechanical properties and extend their service life by providing good thermal stability, light stability and anti-aging properties. Below is a detailed description of some of the key physicochemical properties of dioctyltin dimercaptoacetate.
Physical properties
Appearance: Dioctyltin dimercaptoacetate is usually a light yellow to colorless oily liquid. This is due to its organic structural characteristics that allow it to remain liquid at room temperature.
Solubility: This compound has good solubility and is easily soluble in most organic solvents, such as esters, ethers, ketones, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons and commonly used Plasticizer, but insoluble in water. This solubility characteristic is crucial for its use in polymer processing, allowing for uniform dispersion in the PVC matrix.
Density: Its relative density is approximately between 1.055 and 1.075 (measured at 30°C), which means it is lighter than water, helping to achieve uniform dispersion during certain processing processes .
Melting point and boiling point: Due to the fluidity of its molecular structure, dioctyltin dimercaptoacetate does not have a clear melting point, but has a wide solidification range. Its boiling point is relatively high, usually above hundreds of degrees Celsius. The specific value depends on experimental conditions and measurement methods.
Refractive index: The refractive index is between 1.490 and 1.500 (measured at 30°C). This parameter is of great significance for understanding its optical properties and its application in transparent products.
Viscosity: The viscosity of this compound is low, less than 90mPa·s (measured at 30°C), indicating that it has good fluidity and mixing properties during processing.
Chemical properties
Stability: Dioctyltin dimercaptoacetate is relatively stable at room temperature, but may decompose at high temperatures or in a strong alkaline environment. It has some stability to light and heat, but long-term exposure may still cause performance degradation.
Reactivity: The organotin part of this compound is sensitive to moisture in the air and may slowly hydrolyze, releasing free isooctyl thioglycolate. At the same time, the divalent tin ions contained in it can participate in coordination reactions and form stable complexes with a variety of ligands.
Toxicity and Environmental Impact: Although the information mentions “toxicity of toxic substances”, the specific toxicity level and environmental impact need to be determined based on the latest chemical safety data sheet (MSDS). Organotin compounds are generally considered toxic to aquatic life, and long-term exposure may have adverse effects on human health. Therefore, appropriate safety measures should be taken when using and handling to ensure compliance with environmental and occupational safety standards.
Application Features
In PVC processing, dioctyltin dimercaptoacetate is mainly used as a heat stabilizer, which can effectively inhibit adverse reactions caused by thermal degradation of PVC during processing and use, such as color changes and reduced mechanical properties. Its unique thiol group (-SH) provides excellent antioxidant and UV resistance, helping to improve the transparency and weather resistance of products. It is especially suitable for the production of high-end PVC products such as transparent bottles, plates, and sheets.
Conclusion
To sum up, dioctyltin dimercaptoacetate is an efficient heat stabilizer. Its unique physical and chemical properties make it widely used in the PVC industry. In particular, the field of transparent products shows broad application prospects. However, due to its potential environmental and health risks, increasingly strict regulations on its production and use have driven the industry towards research and development of safer and environmentally friendly alternatives. In the future, how to balance performance and sustainability will be an important topic for research in this field.
Extended reading:
DMCHA – Amine Catalysts (newtopchem.com)
Dioctyltin dilaurate (DOTDL) – Amine Catalysts (newtopchem.com)
