Exhibition Style - Shanghai Peixin Packaging Technology Co., Ltd
40401,21,2026 116 views
As a commonly used raw material in the field of fine chemical engineering, the physical properties of Tada raw materials directly determine their suitability for subsequent processing. In the import process, the following key physical indicators are taken as the core control points, all of which are measured using industry wide testing standards:
1. Appearance and microstructure characteristics
Macroscopic manifestation: Under normal conditions, it appears as a white to off white powdery solid without visible impurities, color blocks, or agglomeration. When imported goods arrive, a screening test must be conducted using a 30 target sieve, and the proportion of residual material must be controlled below 0.1% to ensure that the powder dispersibility meets the subsequent process requirements.
Microscopic observation: Scanning electron microscopy (SEM) is used for microscopic morphology analysis. The observed particles should be irregular sheet-like or columnar, with an average particle size distribution range of 5-20 μ m and a particle size standard deviation of less than 3 μ m to avoid uneven mixing caused by uneven particle size.
2. Thermal properties and measurement methods
Melting point range: determined by differential scanning calorimetry (DSC), with a heating rate set at 10 ℃/min and a nitrogen protective atmosphere (flow rate of 50mL/min), the measured melting point needs to be stable in the range of 302 ℃ -303 ℃, and the half width of the melting endothermic peak needs to be less than 2 ℃. If the melting point deviates from the standard range or the peak shape is abnormal, further purity issues need to be investigated.
Thermal stability: evaluated by thermogravimetric analysis (TGA), the mass loss below 200 ℃ should be less than 0.5% when the temperature is raised from room temperature to 400 ℃ in an air atmosphere, and there should be no obvious decomposition phenomenon below 300 ℃, ensuring that the raw materials will not produce impurities due to thermal decomposition in subsequent high-temperature processing steps.
3. Solubility and optical properties
Dissolution behavior: Under constant temperature conditions of 25 ℃, test the dissolution of raw materials in water (solubility<0.1mg/mL), ethanol (solubility<1mg/mL), and chloroform (solubility>10mg/mL). The dissolution curve should conform to the typical characteristics of hydrophobic organic compounds, and there should be no stratification or precipitation during the dissolution process.
Specific rotation: measured using an automatic polarimeter under the conditions of 20 ℃, sodium lamp (589.3nm), and chloroform solvent (concentration 1.00g/100mL). The measured specific rotation should be within the range of+70.0 ° to+72.0 °, which directly reflects the integrity of the molecular structure. If the deviation exceeds the range, it is judged as unqualified.
