RK-Chem Waterborne polyurethane dispersant technology: How to achieve EU environmental standards with VOC emissions < 5g/L?

With the continuous tightening of VOC (volatile organic compound) emission limits under the EU REACH regulations, traditional waterborne polyurethane dispersants are difficult to meet the < 5g/L ultra-low emission requirements]. RK-Chem broke through the technical bottleneck through the dual path of molecular structure innovation + process optimization, and successfully developed a dispersant system that meets EU environmental standards. The following in-depth analysis from the technical principle to the practical effect:

First, core technology breakthrough: ionic block copolymer design

1.Anchoring group optimization

Sulfonic acid group (-SO3H) is used as the main anchoring group to form a stable coordination bond with the -NCO group in the polyurethane prepolymer, replacing the traditional amine chain extender (easy to produce free amine VOC). The experimental data show that the adsorption energy of sulfonic acid group is 32% higher than that of carboxylic acid group, and the amount of dispersant added is reduced by 20%].

2.Solvent-free RAFT polymerization process

Precise control of molecular weight distribution (PDI=1.1-1.3) via reversible addition-break chain transfer (RAFT) polymerization, avoiding solvents such as acetone and DMF. Compared with the traditional process, the residual VOC was reduced from 50g/L to < 1g/L].

Second, key raw materials and formula innovation

1.Environmentally friendly chain extender alternative

Replacing the ethylenediamine chain extender with AAS salt (2- [Sodium (2-aminoethyl) amino] ethanesulfonic acid) eliminates the risk of release of primary amines and improves dispersion stability (Zeta potential up to -45mV).

2.Nanoscale dispersion coordination technology

The introduction of modified silica particles of 15-30nm reduces the amount of wetting agent (from 3% to 0.8%) through steric hindrance effect, further reducing the source of VOC].

Third, test data and industry certification

1. Authoritative testing and verification

VOC emission: According to SGS test, the VOC content of RD-9208 dispersant system is only 4.2g/L, which is better than the Canadian 5g/L limit]Zero detection of hazardous substances: 16 substances of high concern to SVHC, 24 heavy metals were not detected (refer to GB 18582-2020)]

2. International certification

Passed the EU ECOLOGO and German Blue Angel certification to meet the compliance needs of export-oriented customers such as automobiles and furniture]

Four. Application cases and cost-effectiveness

1. Demonstration of automobile coating enterprises

After a German car company uses RK dispersant:Coating line VOC treatment cost reduced by 60%] Coating salt spray resistance increased from 500h to 1500h (ASTM B117)]

2. Comprehensive cost advantage

Despite the 25% higher unit price of environmentally friendly raw materials, customers saved more than 2 million yuan annually by reducing the amount of additives used (18% lower overall cost) and eliminating VOC treatment fees.