Explanation of various physical properties of catalysts

Explanation of various physical properties of catalysts

Physical properties

Physical properties represent the shape, structure, density, particle size and other properties of the catalyst. They usually include five main items: specific surface area, pore volume, apparent bulk density, wear index, and sieving composition .The following are briefly described:

1. Specific surface area

The specific surface area of ​​a catalyst is the sum of the inner surface area and the outer surface area. The inner surface area refers to the surface area inside the catalyst pores, and the outer surface area refers to the outside of the catalyst pores. The surface area, usually the inner surface area is much larger than the outer surface area. The surface area per unit weight of the catalyst is called the specific surface area.

Specific surface area is an important indicator to measure the performance of catalysts. Different products have different carriers and preparation processes, so there is no direct correspondence between specific surface area and activity.

The method used to determine the specific surface area is the nitrogen adsorption capacity method.

2. Pore volume

Pore volume is a physical quantity that describes the pore structure of a catalyst. The pore structure not only affects the activity and selectivity of the catalyst, but also affects the mechanical strength, life and heat resistance of the catalyst.

Pore volume is the total volume of the micropores in the porous catalyst particles, and the unit is ml/g. The size of the pore volume is mainly related to the catalyst The carriers in are closely related. For the same type of catalyst, the pore volume will decrease and the pore diameter will increase during use.

The method used to measure pore volume is the water drop method.

Z-131: Reactive low-odor gel amine catalyst compound

Z-130: low-odor gel catalyst, balanced gel/foaming

ZR-70: Low odor catalyst for packaging foam and molded foam on vinyl skins. Good balance of foaming and gelling

ZR-40 (pentamethyldipropylenediamine): Particularly effective for cold molded high-resilience foams, low-odor gel and foaming catalyst with good balance

LE-310: Low odor reactive gel catalyst applied to large sponges, new lowVOC amine gel catalyst, amine content exceeds 95%

LE-530: Reactive gel catalyst, used in various polyurethane foam products

DPA: Low-odor gel catalyst, outstanding balance and versatility provide good fluidity

TAP 1-methyl-4-(2-dimethylaminoethyl)piperazine: Excellent trimerization catalyst that can improve fluidity

DMDEE (2,2′-dimorpholindiethyl ether): Strong foaming catalyst, providing stable prepolymer system

DMAEE: low-density full-water rigid foam and low-density semi-rigid foam

BDMAEE bis-(2-dimethylaminoethyl) ether：High-efficiency foaming catalyst

BDMA (N,N-dimethylbenzylamine)：Polyurethane rigid foam catalyst, epoxy accelerator

DMEA (N,N’-dimethylethanolamine): Neutralizes acids in some rigid foam systems,

PMDETA (pentamethyldiethylenetriamine): Especially effective for HCFC/water-foamed hard foam, similar to PC5