Rubber crosslink density analyzer - temperature dependent nuclear magnetic resonance

Crosslinking density refers to the number of cross-linking bonds in a cross-linked polymer, usually expressed in terms of the molecular weight of the network chains. The higher the crosslinking density, that is, the more crosslinking bonds per unit volume, and the greater the degree of crosslinking.

In the field of polymers, especially rubber, crosslinking density and its uniformity are important indicators for controlling rubber quality. The higher the crosslinking density, the better the mechanical strength, resilience, heat resistance, and tensile strength. However, excessive cross-linking can lead to a decrease in impact strength. The testing and evaluation of crosslink density is a very important part of product development, product quality assessment, and quality control.

Rubber crosslink density analyzer - temperature dependent nuclear magnetic resonance method:

H-NMRRelaxation is caused by the magnetic dipole interactions between molecules and within molecules.The crosslinking density can be determined by the transverse relaxation parameterT2Calculate it out.

Rubber crosslink density analyzer - temperature dependent nuclear magnetic resonanceBy testing the mixed rubber compoundNMRAttenuation can obtain its physical crosslink density, which can be used to measure the properties of vulcanized rubberNMRAttenuation can obtain the total crosslink density, and through program calculation, the chemical crosslink density of the vulcanized rubber can be obtained simultaneously.

Rubber crosslink density analyzer - Basic parameters of temperature dependent nuclear magnetic resonance:

1. Magnet type: permanent magnet; Magnetic field strength: 0.5 ± 0.05T;
2. Effective detection range of the sample: Ø 8.5mm × H20mm;
3. Sample temperature control range: from room temperature to 130 ℃ (standard)
4. High end variable temperature module: from room temperature to 200 ℃ (optional);
5. Imaging function (optional);

Rubber crosslink density analyzer - temperature dependent nuclear magnetic resonance