From dispersion to efficiency enhancement:
Five core competitive advantages of polyurethane carbon black viscosity reduction dispersants
The core advantage of polyurethane carbon black viscosity reduction dispersants is that they optimize the dispersion
behavior of carbon black in polyurethane systems and simultaneously solve the three major problems of viscosity control,
performance improvement and processing efficiency. The following analysis is carried out from three dimensions:
technical mechanism, performance breakthrough and process value:
1. Efficient dispersion: breaking the agglomeration barrier and releasing the potential of carbon black
Nanoscale dispersion technology
Carbon black particles are very easy to form agglomerates in polyurethane due to their high surface energy and large
specific surface area (particle size can reach micrometers), resulting in uneven blackness of the material and decreased
mechanical properties. The dispersant forms a steric barrier by anchoring on the surface of carbon black (such as through
π-π conjugation or hydrogen bonding), so that the particle spacing is expanded from <100nm to >500nm, completely
eliminating agglomeration.
Interface wettability revolution
The interface tension between traditional carbon black and polyurethane is high (>30mN/m), which makes dispersion
difficult. The dispersant molecular chain contains both carbon black-loving groups (such as nitrogen-containing heterocycles)
and polyurethane-loving groups (such as polyether segments), which can reduce the interfacial tension to <5mN/m and shorten
the wetting time of carbon black in the prepolymer from 30 minutes to 5 minutes.
2. Precise viscosity reduction: balancing processability and material properties
Viscosity controllability
Polyurethane system viscosity that is too high will lead to a surge in processing energy consumption (such as a 40% increase
in the pumping pressure of a two-component adhesive) and poor coating leveling; too low viscosity may cause filler
sedimentation. Dispersants can achieve a 30%-60% reduction in viscosity by regulating the molecular weight distribution
(such as introducing a comb-like structure) while maintaining the thixotropy of the system (such as a yield stress >50Pa)
to ensure construction stability.
High-solid formula support
Due to viscosity limitations, the solid content of traditional systems is usually <50%. Dispersants increase the solid
content to more than 65% by reducing the internal friction between molecules, while maintaining a viscosity of
<5000mPa·s, significantly reducing the use of organic solvents (VOCs emissions are reduced by 50%-70%).
3. Performance enhancement: the leap from microstructure to macro performance
Double mechanical properties
Uniformly dispersed carbon black can be used as a physical cross-linking point to form an "island structure" with the
polyurethane molecular chain. In tire tread rubber, the dispersant increases the effective filling rate of carbon black from
60% to 85%, the tensile strength from 18MPa to 25MPa, and the wear resistance (DIN wear) is reduced by 30%.
Functional properties synergy
In conductive polyurethane, the dispersant reduces the volume resistivity from 10⁶Ω·cm to 10³Ω·cm by regulating thecarbon black spacing (<100nm), and maintains the tensile strength>15MPa; in the absorbing material, the carbon black
and magnetic filler are synergistically optimized to disperse, so that the bandwidth of the reflection loss <-10dB in
the 8-18GHz frequency band is widened by 40%.
4. Process adaptability: universal value across systems and processes
Multi-system compatibility
The molecular structure of the dispersant can be customized and is compatible with solvent-based, water-based and
solvent-free polyurethane systems. For example, self-emulsifying segments (such as polyethylene glycol monomethyl
ether) are introduced into the aqueous system to accurately match the HLB value with the hydrophilicity of carbon
black; in the solvent-free system, the molecular chain rigidity is adjusted to avoid the decrease of dispersion stability
during high-temperature processing.
Full process coverage
From high-speed dispersion (3000rpm) to low-shear blending (50rpm), from spraying to 3D printing, the dispersant
can maintain stable performance. In photocuring 3D printing, the dispersant reduces the sedimentation rate of carbon
black in photosensitive resin by 90% and increases the bonding strength between printed layers by 20%.
5. Win-win situation of environmental protection and economy
Green chemistry breakthrough
The new dispersant is synthesized from bio-based raw materials (such as ricinoleic acid), with a biodegradation rate
of >60% (28 days), and does not contain hazardous substances such as APEO and nonylphenol, complying with
REACH and RoHS regulations. After application in automotive interior coatings, VOCs emissions are reduced from
420g/L to 120g/L.
Cost-effectiveness optimization
The dispersant reduces the overall cost by 15%-25% by improving the utilization rate of carbon black (reducing the
dosage by 10%-20%) and reducing processing energy consumption (such as shortening the mixing time by 30%). In the
production of building sealants, a single production line saves more than 500,000 yuan in energy consumption costs per year.
Summary:
Double breakthrough in technical value and industrial significance
The core advantage of polyurethane carbon black viscosity reduction dispersant can be summarized as "one dose with
multiple effects" - a single auxiliary agent is used to achieve multiple functions such as dispersion, viscosity reduction,
toughening, and electrical/thermal conductivity. Its technical value lies in breaking the paradox of "viscosity reduction
means loss of performance" of traditional dispersants, and achieving a dynamic balance between performance and
processability through molecular design; its industrial significance lies in promoting the upgrading of polyurethane
materials to high performance, functionalization, and greening, and helping the automotive, electronics, construction
and other industries achieve carbon neutrality goals. In the future, with the development of nano-dispersion
technology and intelligent responsive dispersants, its application boundaries will be further expanded to
cutting-edge fields such as biomedicine and flexible electronics.
