# Polyurethanes (MDI, TDI, polyols): Correlation Prices it moves with, and why Source page: https://www.materialinsights.org/chemicals/polyurethanes/correlation/ Polyurethanes are made by reacting an isocyanate, MDI or TDI, with polyols. MDI comes from benzene, chlorine and formaldehyde, and polyols mostly from propylene oxide, so prices follow those chains and insulation, furniture, bedding and car demand. Proxy **US PPI: thermosetting resins and plastics materials** index (BLS base period) · monthly, Jan 2006 to Sep 2026 There is no free public price for Polyurethanes (MDI, TDI, polyols) itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item. #### What its price moves with Selected link ##### Polyurethanes (MDI, TDI, polyols) and Benzene Monthly changes 0.22 weak correlation 12-month changes 0.49 moderate correlation Last 5 years 0.29 monthly changes Lead or lag none No clear lead or lag Price function, Jan 2006 to Sep 2026 Polyurethanes (MDI, TDI, polyols) ≈ 205.6 × (Benzene)^0.03 R² 0.01 On this fit, a 10% higher benzene price goes with a 0.3% higher Polyurethanes (MDI, TDI, polyols) price over the long run. Units: index (BLS base period) and index (BLS base period). The fit is loose, so treat the function as a rough guide. Chart: Polyurethanes (MDI, TDI, polyols) and Benzene prices rebased to 100 at Jan 2006, log scale Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size. Chart: Polyurethanes (MDI, TDI, polyols) price against Benzene price, monthly, log scales, with fitted line Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic. Chemical [Bz Benzene](https://www.materialinsights.org/chemicals/benzene/)Feedstock 0.22 Benzene is turned into nitrobenzene, aniline and then MDI, while TDI comes from toluene, so aromatics costs flow into isocyanates. The petrochemical proxy moves with the thermosetting proxy at 0.22 monthly, a weak tie for a broad resin index. weak co-movement month to month · 249 months Show charts Chemical [PO Propylene oxide](https://www.materialinsights.org/chemicals/propylene_oxide/)Feedstock 0.24 Polyether polyols, made from propylene oxide, are the other main ingredient of most foams. The basic organics proxy moves with the thermosetting proxy at 0.24 monthly and 0.74 yearly. Polyol makers pass propylene oxide costs on. weak co-movement month to month · 249 months Show charts Chemical [Cl2 Chlorine](https://www.materialinsights.org/chemicals/chlorine/)Input 0.23 MDI and TDI are made with phosgene from chlorine, and the chlorine is recycled as hydrochloric acid, so isocyanate plants sit beside chlor-alkali units. The alkalies index moves with the proxy at 0.23 monthly and 0.67 yearly. weak co-movement month to month · 249 months Show charts Energy [Gas Natural gas](https://www.materialinsights.org/energy/natural_gas/)Energy cost 0.17 Gas sets the cost of the carbon monoxide for phosgene and the energy for these chains, especially in Europe. European gas moves with the thermosetting proxy at 0.17 monthly and 0.74 yearly. little or none co-movement month to month · 249 months Show charts Energy [HP Heat pumps, air conditioning and refrigeration](https://www.materialinsights.org/energy/e_heat_pumps/)End use 0.27 Rigid polyurethane foam insulates refrigerators, freezers, cold stores and many cooling units. The air-conditioning and refrigeration equipment index moves with the proxy at 0.27 monthly and 0.69 yearly. Appliance makers buy foam systems on contracts. weak co-movement month to month · 249 months Show charts How to read these numbers **Correlation of monthly changes** (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak. **12-month changes** compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs. **Price function** is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)^β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation. **Lead or lag** checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months. Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link. Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site. ## Other sections - [Summary](https://www.materialinsights.org/chemicals/polyurethanes/index.md) - [Overview](https://www.materialinsights.org/chemicals/polyurethanes/overview/index.md) - [Production route](https://www.materialinsights.org/chemicals/polyurethanes/routes/index.md) - [Production](https://www.materialinsights.org/chemicals/polyurethanes/production/index.md) - [Feedstocks](https://www.materialinsights.org/chemicals/polyurethanes/feedstocks/index.md) - [Cycles](https://www.materialinsights.org/chemicals/polyurethanes/cycles/index.md) - [Trading](https://www.materialinsights.org/chemicals/polyurethanes/trading/index.md) - [Movement](https://www.materialinsights.org/chemicals/polyurethanes/movement/index.md) - [Regulation](https://www.materialinsights.org/chemicals/polyurethanes/regulation/index.md) - [Characteristics](https://www.materialinsights.org/chemicals/polyurethanes/characteristics/index.md) - [Emissions](https://www.materialinsights.org/chemicals/polyurethanes/emissions/index.md) - [Relationships](https://www.materialinsights.org/chemicals/polyurethanes/links/index.md)