Next-Generation Polyurethane Elastomers: Unlocking the Ultimate Potential of Polyurethanes with ROPOL Polycarbonate Polyols
Unlike traditional polyester and polyether polyols, the ROPOL polycarbonate polyols offer significant advancements in polyurethane elastomer technology, affording unparalleled performance and exception resistance to:
- High Temperatures - Consistent performance under intense heat
- Superior Hydrolysis Resistance - Excellent resistance to degradation in moist environments
- Enhanced Weathering - Longevity and stability in outdoor applications
- High Transparency - Excellent clarity and durability
- Robust Solvents and Chemical Resistance - Resistance to solvents, oil and chemicals
- Exceptional Abrasion Resistance - Long-lasting durability against wear and tear
- Waterborne Polyurethane Dispersions (PUDs)
- Artificial leather coatings
- Protective films, including paint protective film
- Oil field and mining parts
- High-speed wheels and rollers
- Thermoplastic Polyurethanes (TPUs)
- Exterior Coatings
- Adhesives
- Optical devices and solar panels
- Pipe interior linings
- Electrical/electronic encapsulation
- Medical devices and tubing
The Gantrade-Cromogenia Advantage
Gantrade and Cromogenia combine global expertise in urethane intermediates—polyols, chain extenders, curatives, and isocyanates—to deliver high-performance polyurethane elastomer solutions. With Cromogenia’s advanced polycarbonate diol production facilities, decades of R&D, forward integration, and diverse portfolio, paired with Gantrade’s market reach and technical expertise, we offer a powerful partnership. Together, we provide tailored solutions and support to help you overcome challenges and seize new opportunities.
Understanding the Chemistry of ROPOL Polycarbonate Diols
Polycarbonate diols are produced through a controlled carbonate exchange polymerization (CEP) process using dialkyl carbonate and aliphatic diols (or diol mixtures for amorphous PCD copolymers). When dimethyl carbonate (DMC) is the carbonate source, methanol is the by-product. The process involves two stages: first, forming a low molecular weight PCD oligomer, and second, advancing it to the desired molecular weight under higher temperature and reduced pressure.
The following ROPOL Polycarbonate Diols are currently available:
Standard Products:
- 1,6-Hexanediol carbonate homopolymer (white solid)
- 1,6-Hexanediol/1,5-pentanediol carbonate copolymer (viscous liquid)
Next Generation Products:
- 1,6-Hexanediol/1,4-butanediol carbonate copolymer (liquid)
- 2-Methyl-1-3, propanediol carbonate homopolymer (liquid)
- 2-Butyl-2-ethyl-1,3-propanediol homopolymer (viscous liquid)
The compositional architectures of the standard ROPOL polycarbonate diol grades are shown below. The specific compositional architectures of the next generation grades are available upon request
Physical Properties of Standard Polycarbonate Grades
The table below shows the Tg and the Tm of the standard ROPOL PCDs. The Tg's and Tm's were determined using Differential Scanning Calorimetry (DSC).
| Tg, °C | Tm, °C | |
| ROPOL PC11 | -74 | 40-45 |
| ROPOL PC12 | -64 | 44-49 |
| ROPOL PC21 | -59 | - |
| ROPOL PC22 | -63 | - |
The C5/C6 copolymers, ROPOL PC21 and PC22 disrupt the crystallinity of the homopolymers and are amorphous compositions.
Polyurethane Mechanical Properties
Polyurethanes were produced using a bulk 2K PCD prepolymer process. MDI prepolymers of the polycarbonate diols were extended using 1,4-butanediol at 60ºC and homogenized for two minutes, poured into molds, and post-cured at 100ºC for 12 hours. The ratio of the polycarbonate diol, MDI, and BDO was varied to adjust the hard block content and the Durometer values. Tensile properties for two different hard block contents are shown in the table below.
| HDO Homopolymer 1000 MW | HDO Homopolymer 2000 MW | HDO/PDO Co-Polymer 2000MW | ||||
| Hard Block % | 37 | 48 | 40 | 50 | 40 | 51 |
| Durometer | 94 A | 97 A | 96 A | 59 D | 96 A | 60 D |
| Modulus, psi | 1,885 | 13,340 | 5,365 | 21,320 | 1,450 | 1,885 |
| Tensile Strength, psi | 5,511 | 4,786 | 5,656 | 4,061 | 6,961 | 8,702 |
| Elongation, % | 330 | 150 | 311 | 157 | 108 | 39 |
| TG, °C | -16 | -15 | -34 | -33 | -30 | -32 |
Polyurethane properties using standard polycarbonate diols at various hard block contents are detailed in A. Eceiza et al., Polymer Engineering and Science, pp. 297, 2008.
The higher glass transition temperatures (Tg) of polyurethanes compared to their base polyols indicate micro-phase mixing between the hard and soft segments. This enhanced mixing in polycarbonate-based polyurethanes is due to strong intermolecular forces, such as dipole-dipole and hydrogen bonding interactions, between the carbonate linkages of the soft segments and the urethane linkages of the hard segments. Polyurethanes based on 2000 MW polyols exhibit higher micro-phase separation and a more ordered polyol phase, resulting in lower Tg values. These intermolecular forces and phase behaviors significantly influence the mechanical properties of polyurethane formulations and should be carefully considered.
Polycarbonate diol homopolymers in polyurethanes exhibit a strong tendency to stress-crystallize, as shown by the steeper slope in the stress-strain curve during crystallization. In contrast, amorphous co-polycarbonates show reduced strain-induced crystallization under elastic deformation. This results in co-polymers combining high tensile strength with high elongation, enhancing toughness.
The best elevated-temperature property retention (e.g., tensile and tear strength) has been reported in polyurethanes based on polycarbonate diol-PPDI prepolymers chain-extended with HQEE or polycarbonate diol-TDI prepolymers cured with MCDEA, even after aging at temperatures up to 150°C. Additionally, HQEE is an excellent chain extender for polycarbonate diol-MDI prepolymers, enhancing hard block phase separation.
Why Polycarbonate Polyols Excel in Polyurethanes
Increasing the carbonate (CO3) content in polyols improves thermal, chemical, and solvent resistance, as well as abrasion resistance and tear strength. Reducing the chain length of the diol intermediate increases the carbonate content, leading to enhanced performance properties in the resulting polyurethane elastomers, as illustrated in the figure below. These improvements are essential for high-performance elastomers designed for demanding environments.
The figure shows that the homopolymer with the lowest carbonate content demonstrates better abrasion and oil resistance due to crystallization in the soft block. However, Next Generation polycarbonate diols, with higher carbonate content in the soft block, offer improved performance compared to standard grades, enhancing key properties in polyurethane elastomers.
ROPOL Polycarbonate Polyol Attributes:
Attributes of the ROPOL polycarbonate polyols in polyurethanes include the following:
- Excellent hydrolytic stability & low water absorption
- Maximum temperature stability with low-temperature flexibility
- High chemical & oil resistance
- Weatherability & UV resistance
- Excellent adhesion in harsh environments
- Superior durability, impact, tear, and abrasion resistance
- Excellent mechanical properties and toughness
- Long-term retention of designed properties in aggressive environments
- Self-healing characteristics and scratch repair at ambient temperatures
Applications for the ROPOL Polycarbonate Polyurethane Elastomers
Key applications for ROPOL polycarbonate diol-based polyurethanes include waterborne polyurethane dispersions (PUDs), artificial leather coatings, protective films (e.g., paint protection), oil field and mining components, pipe linings, exterior coatings, adhesives, electrical/electronic encapsulation, optical and solar panel devices, medical devices and tubing, high-speed and industrial wheels and rollers, industrial roll coatings, thermoplastic polyurethanes (TPUs), and other demanding uses requiring superior performance.
Polyurethanes made with 1000 MW polycarbonate polyols demonstrate the fastest self-healing kinetics and excellent surface characteristics in coatings, films, and cast parts. This performance results from a balanced interaction between carbonate dipole-dipole forces in the soft segments and urethane-carbonate hydrogen bonding between the phases.
ROPOL Polycarbonate Diol Specifications
Below are the sales specifications for four standard grades of ROPOL polycarbonate diols and four next-generation grades from Cromogenia. ROPOL PC12 are crystalline homopolymers, whereas ROPOL PC21 and PC22 are amorphous copolymers, liquid at room temperature.
|
ROPOL PC11 |
ROPOL PC12 | ROPOL PC21 | ROPOL PC22 | |
| Composition |
1,6-Hexanediol Carbonate: Homopolymer |
1,5-Pentanediol & 1,6-Dexanediol: Carbonate Copolymer | ||
| Appearance | White Solid | White Solid | Viscous Liquid | Viscous Liquid |
| Target Molecular Wt. | 1000 | 2000 | 1000 | 2000 |
| Hydroxyl Value, Mg.KOH/g | 110-115 | 52-58 | 108-115 | 54-59 |
| Melting Point, °C | 40-45 | 44-49 | - | - |
| Viscosity, cPs @ 70°C | 1000 | 2700 | 1850 | 2150 |
| Moisture Content, % | 0.05 max | |||
| Color, APHA | 100 max | |||
The following table provides the sales specifications for four next-generation grades of ROPOL polycarbonate diols. Notable are the low viscosities of the ROPOL PC50 and ROPOL PC413 polycarbonate diols.
|
ROPOL PC41 |
ROPOL PC50 | ROPOL PC32 | ROPOL PC413 | |
| Composition |
2-Butyl-2ethyl-1-3-Propanediol: Carbonate Homoploymer |
2-Methyl-1-3-Propanediol: Carbonate Homopolymer |
1,4-Butanediol & 1,6-Hexanediol: Carbonate Copolymer |
|
| Appearance | Viscous Liquid | Viscous Liquid | Non-Fluid | Liquid |
| Target Molecular Wt. | 1000 | 500 | 2000 | 1300 |
| Hydroxyl Value, Mg.KOH/g | 110-115 | 52-58 | 108-115 | 54-59 |
| Melting Point, °C | - | - | 115-220 | - |
| Viscosity, cPs | 1800@ 70°C | 2000@50°C | 6300@80°C | 1100@20°C |
| Moisture Content, % | 0.05 max | |||
| Color, APHA | 100 max | |||
All the above grades have been produced commercially. The ROPOL PC50 and ROPOL PC413 grades, as well as the standard grades, are all used in Paint Protective Film (PPL).
Tailored Solutions for the Industry
The Gantrade and Cromogenia partnership provides access to a comprehensive portfolio of high-performance polycarbonate polyols for polyurethane elastomers. From waterborne coatings to medical devices, these advanced materials deliver next-generation performance, setting new standards in durability and reliability. Discover how ROPOL polycarbonate polyols can enhance your applications—contact Gantrade today for tailored solutions to meet your needs.
