Generational evolution of isocyanates: from TDI/MDI to NDI/PPDI/TODI

Generational evolution of isocyanates: from TDI/MDI to NDI/PPDI/TODI

With sustainability and carbon neutrality becoming increasingly important, bio-based polyols are taking on a more significant role in the polyurethane industry. Unlike conventional systems that rely heavily on petrochemical resources, bio-based polyols are produced from renewable sources such as vegetable oils, starch, and even carbon dioxide. This not only helps reduce the overall carbon footprint but also adds value for companies working toward ESG and long-term sustainability goals.

That said, bio-based polyols still face certain challenges. Polyols derived from natural feedstocks often show irregular functionality and broad molecular weight distribution, which can reduce consistency and limit mechanical performance. This makes them less suitable for demanding applications such as heavy-duty PU wheels, oil seals, or automotive damping parts.

By combining bio-based polyols with specialty isocyanates, such as Johnson Fine Chemical’s HARTDUR 115 (1,5-naphthalene diisocyanate), HARTDUR 118 (3,3'-dimethyl-4,4'-biphenyl diisocyanate), and HARTDUR 120 (p-phenylene diisocyanate), these shortcomings can be addressed. With their rigid aromatic backbones and high crystallinity, these isocyanates bring excellent tensile strength, abrasion resistance, heat and chemical stability of polyurethane materials, while also delivering excellent dynamic fatigue performance, low compression set, and long-term durability. This makes them ideal for use in automotive NVH (Noise, Vibration, Harshness) components as well as precision seals and gaskets.

Another key advantage is their higher NCO content (%), which allows for greater use of bio-based polyols in the formulation while still maintaining the high mechanical performance and durability of the polyurethane material. This not only supports ESG and carbon-reduction targets but also ensures performance on par with traditional petrochemical-based systems, opening new opportunities for sustainable polyurethane materials.