MAGNESOL® Polysorb 30/40

1 of 6 products in this brand
MAGNESOL® Polysorb 30/40 is a synthetic magnesium silicate adsorbent designed for deep purification of polyols which are generally used in the production of urethane polymers. Purification of polyols by adsorption using synthetic magnesium silicate is widely recognized as the most effective way to produce high quality polyols. Synthetic magnesium silicate is an amorphous material with high pore volume and active surface area. Due to the unique structure and surface chemistry, MAGNESOL® magnesium silicate adsorbents can selectively and very efficiently remove alkali metal catalysts, as well as other polar compounds from various polyols and surfactants. High adsorptivity and excellent filtration characteristics permit these adsorbents to be easily used in industrial conditions.

Chemical Name: Magnesium Silicate

Chemical Family: Silicates

Functions: Adsorbent, Anti-Caking Agent, Filler, Filtration Aid

Features: Anti-Static

Synonyms: Magnesium metasilicate (MgSiO3), Magnesium silicate (Mg2(SiO3)2), Magnesium silicon oxide (MgSiO3)

Knowde Enhanced TDS

Identification & Functionality

Chemical Family
Chemical Name
Molecular formula
MgO-x SiO₂ – y H₂O
EINECS No.
2156811

Features & Benefits

Industrial Additives Features
Benefits of Magnesium Silicate Adsorbents

Adsorbent type and adsorbent dose are two of the most important factors influencing the residual potassium content for specific polyols. MAGNESOL® adsorbents have excellent capability for color removal from polyols and surfactants. Color may be lowered below 30-50 APHA during the purification process. Removal of potassium and sodium catalysts below 20 ppm significantly improves color of final product.

MAGNESOL® adsorbents provide:

  • Low residual potassium content to help meet polyol and surfactant specifications
  • 25-40% less adsorbent dose requirement which can reduce filter cake disposal
  • Lower pH of treated polyol which can improve or eliminate the neutralization step
  • Faster filtration time which improves productivity
  • Excellent color removal for improved polyol quality

Applications & Uses

Markets
Industrial Additives End Use
Use Level
1 - 3 wt %
Product Selection Guide
Product HMR Polysorb 30/40 Cartridge Grade
KOH adsorption* - dry 210 190 185
KOH adsorption* - wet 220 210 210
Filtration rate Standard Moderate Fast

*KOH adsorption is determined in a special laboratory test utilizing di-propylene glycol (DPG) as a model polyol.

General guidance for adsorbent selection:

  • If the polyol has a molecular weight below 1000, pH above 12, and low viscosity, then HMR and Polysorb 30/40 will be the adsorbents of choice to achieve potassium content below 5 ppm
  • If the polyol has a molecular weight between 1000-5000, high pH, and high viscosity, then Polysorb 30/40 and Cartridge Grade will be more preferential adsorbents for potassium and color removal.
  • Cartridge Grade is recommended to use when high filtration rate is required, specifically when pressure leaf filters with centrifugal discharge are used.

 

Applications
  • Adsorbent for the purification of polyols & surfactants
  • Filter aid, Catalyst supports, Carriers, Reinforcing fillers

Properties

Physical Form
Appearance
White powder
Taste
Tasteless
Odor
Odorless
Insoluble in
Water
Typical Properties
ValueUnitsTest Method / Conditions
pH9.7
Surface Area, BET350m²/g
Particle Size (Mean diameter of Volume distribution)50microns
KOH Adsorption*190mg/g
Assay
ValueUnitsTest Method / Conditions
MgO (Ignited Basis)min. 15.0%
SiO₂ (Ignited Basis)min. 67.0%
Specifications
ValueUnitsTest Method / Conditions
Magnesium Silicate73%
Loss on Ignition (at 900°C)25%
SO₄ Contentmax. 2wt %
DPG Filter Timemax. 150s
KOH Adsorptivitymin. 180mg KOH/g Magnesol®
Loss on Ignition (at 900°C, dry basis)max. 15.0%
Loss on Drying (at 105°C, as packaged)max. 20.0%
Soluble Saltsmax. 3.0%
Free Alkali (as NaOH)max. 1.0%
Note

* KOH adsorption is determined in a special laboratory test utilizing di-propylene glycol (DPG) as a model polyol.

Regulatory & Compliance

Certifications & Compliance

Technical Details & Test Data

Particle Size Distribution

Typical Particle Size Distribution of MAGNESOL® adsorbents used for polyol

MAGNESOL® Polysorb 30/40 - Particle Size Distribution

Operating Conditions Effect on Adsorbent Performance
  • Addition of water to the polyol-adsorbent suspension prior to heating and filtration promotes and accelerates removal of the catalyst from the crude polyether polyols. Water addition enhances potassium transfer from the polyol phase to the water phase and promotes activation of sites on the surface of the adsorbent in the process of polyol purification.
  • Water addition of 0.3% or greater in some polyols can significantly increase the performance of MAGNESOL® adsorbents. The optimum water concentration can be determined in the laboratory or in pilot plant tests. If water addition is used to enhance adsorption, a dehydration step is required to achieve a water specification in the finished polyol.
  • The typical polyol treatment temperature varies from 85°C to 140°C and depends on the polyol chemistry, viscosity, and process conditions. The optimum treatment temperature will vary with each process. In general, the higher the treatment temperature, the better the efficiency of polyol purification with synthetic magnesium silicate adsorbents. Therefore, at higher temperature, the adsorbent dose amount can be reduced. Higher temperature is desirable as long as the polyol is not adversely affected, and process safety criteria are not violated.
  • After completion of polyol purification by adsorption, MAGNESOL® adsorbents are separated from the polyol by filtration using an appropriate filtration equipment.
  • The typical polyol purification process requires from 4 to 6 hours of operation and uses 6 separate steps in sequence:
    • MAGNESOL® adsorbent addition to neutralization vessel.
    • Mixing adsorbent slurry with agitation only.
    • Water addition to agitated polyol slurry.
    • Filtration with polyol recirculation through the filter.
    • Dehydration (stripping) to control residual water content.
    • Transfer polyol to finished vessel through the filter.
  • In some cases, specifically for hydrophobic polyols and non-ionic surfactants, the water addition step can substantially improve not only catalyst removal efficiency, but also polyol filtration time due to the viscosity reduction and adsorbent particles coagulation and agglomeration in the filter cake.
  • Sodium hydroxide is also used as the catalyst for polymerization reaction in polyol and surfactant production. Affinity of magnesium silicate adsorbents for sodium removal is lower than that of potassium due to the ion hydration effect.

Packaging & Availability

Packaging Type
Packaging Information

20 kg, 25 kg, or 50 lb net weight multiwalled paper bag; 400 lb super sack.