GB/T 28610-2020 in English

Methyl vinyl silicone rubber is divided into 4 grades according to the mole fraction of vinyl chain segments:

• MVQ110 series: 0.03-0.24% (vinyl end-capped)
• MVQ112 series: 0.03-0.24% (methyl end-capped)

The relative viscosity-average molecular weight is uniformly required to be 45×10⁴-85×10⁴, and customized adjustment of ±1×10⁴ is allowed.

Dual methods for molecular weight determination:

1. Infrared sensitivity method (arbitration method): using Ubbelohde viscometer, accuracy ±0.01℃
2. Mooney viscometer method (fast method): establish ML(1+4)100℃ calibration curve

Note: The allowable difference for parallel determination is ≤1×10⁴

Manufacturers should focus on:

• Establish a corresponding database of Mooney viscosity and molecular weight
• Near infrared spectroscopy (GB/T 36691) for rapid detection of production lines
• Volatile matter determination is strictly controlled in an environment of 150℃±2℃