Polyether Polyols & Prepolymers for CASE Applications (Coatings, Adhesives, Sealants & Elastomers): Sourcing Guide to Santos, Brazil (2026)

Quick Summary for Coatings, Adhesives, Sealants & Elastomer Producers

CASE refers to Coatings, Adhesives, Sealants and Elastomers. PPG 1000, 2000 and 3000 are common difunctional polyether polyols with hydroxyl values of approximately 112 / 56 / 37 mg KOH/g respectively, a functionality of 2.0 and a water content of ≤ 0.05%. They are used in cast PU elastomers, 2K PU coatings and waterproofing membranes, 1K / 2K sealants and adhesives, and as soft segments and toughening components. Ocean transit from Ningbo to Santos, Brazil typically takes 28 to 34 days, depending on carrier and sailing schedule. We supply 200 kg steel drums, 1,000 kg IBC totes and ISO Tanks, each shipment accompanied by a batch COA, TDS and SDS.

1. Direct Overview

CASE formulations select polyether polyols on the basis of molecular weight, functionality and water content. Higher molecular weight grades such as PPG 3000 deliver lower hardness and greater flexibility, while PPG 1000 offers higher reactivity and hardness potential. Strict water content control (≤ 0.05%) keeps the NCO stoichiometry predictable and limits CO2 side reactions and bubbles. In Brazil, local producers of coatings, sealants, rollers and sealing parts commonly build 2K coating and waterproofing systems around PPG 1000 / 2000 blends, formulate 1K / 2K sealants and adhesives with PPG 2000 / 3000, and cast elastomer rollers, wheels and seals using PPG 1000 / 2000 combined with MDI or TDI prepolymers. DOBO Chemical supplies these grades from Ningbo Port to Santos with batch COA traceability and consistent lot-to-lot quality.

2. Typical Specifications: PPG 1000 / 2000 / 3000

Consistent hydroxyl value, viscosity and water content are essential to reproducible NCO stoichiometry and stable processing in coatings, sealants and cast elastomer lines.

3. CASE Application Matrix

The table below maps common CASE end-uses to recommended PPG grades, typical NCO index ranges and the key property drivers for each system.

4. Formulation Formulas

The following standard calculations support CASE formulation work, covering hydroxyl value conversion, isocyanate demand and prepolymer free NCO estimation.

Equivalent weight (g/eq) = 56,100 / Hydroxyl value (mg KOH/g)

This converts a measured hydroxyl value into an equivalent weight, the basis for all NCO stoichiometry and for comparing 1000 / 2000 / 3000 grade polyols on a reactive basis.

Mass of MDI = [ ( Blend hydroxyl value / 56,100 ) + ( Water content (pbw) x 2 / 18.015 ) ] x ( 42.02 / (NCO% / 100) ) x NCO index

This estimates the MDI mass required per 100 parts of polyol blend, accounting for both the hydroxyl content and the water present in the system, adjusted by the isocyanate NCO content and the target index.

%NCO_free = [ ( MDI pbw x NCO%_MDI / 100 ) - ( 42.02 x Polyol pbw x Hydroxyl value / 56,100 ) ] / Total pbw x 100

This estimates the free NCO content of a prepolymer after the reaction between the polyol and the isocyanate, used to verify prepolymer specification and subsequent chain extension or curing ratios.

5. Packaging, Documentation & Transit to Santos

• Packaging: 200 kg steel drums (80 drums / 20ft FCL), 1,000 kg IBC totes, 24,000 L ISO tanks for bulk.
• Typical ocean transit from Ningbo to Santos: 28–34 days (varies by carrier and sailing schedule); Paranaguá and Itajaí routed via transshipment.
• Documents per shipment: batch COA, TDS, SDS, commercial invoice, packing list, certificate of origin.
• Import compliance: importers should confirm current Brazilian import requirements and NCM classification with their customs broker.

6. Frequently Asked Questions