Unsaturated polyester resins: Feedstocks

Why styrene and maleic anhydride set the cost

What this tab covers What it is made from and what it feeds: the raw materials and energy per tonne with their share of cost (linked to the commodity table), who is low-cost and why, and the chemicals made from it.

UPR is about one-third styrene and two-thirds polyester made from anhydrides and glycols, so its cost tracks styrene, maleic anhydride and propylene glycol. Raw materials are most of the cost, plants are small batch units, and freight is expensive because resin is flammable and has a short shelf life. That is why UPR is made close to its users rather than in a few giant plants.

Inputs per tonne

Input	Quantity per tonne	Role	Share of cost	Source
Oil Crude oil	about 0.30-0.40 t	reactive diluent and crosslinker	about 35% of raw-material cost (indicative)	styrene tile; indicative
Gas Natural gas	about 0.18 t (stoichiometric, 1:1:2 ortho)	unsaturation for crosslinking	maleic anhydride was 51.26% of 2025 raw-material revenue (Mordor)	Mordor via GII 2026; stoichiometry
Oil Crude oil	about 0.26 t (stoichiometric, 1:1:2 ortho)	saturated acid, stiffness	about 15-20% (indicative)	stoichiometry; indicative
Oil Crude oil	about 0.27 t (stoichiometric)	glycol backbone	about 20% (indicative); PG CAGR 5.70% (Mordor)	PO and MEG tiles; Mordor
Co Cobalt	about 0.1-0.5% cobalt octoate solution and 1-2% MEKP (indicative)	cure system	outside resin cost	indicative
Qz Silica sand	about 0.3-2 t per t resin in the composite (indicative)	reinforcement and filler, not part of the resin	outside resin cost	indicative

Who is low-cost, and why

Large Chinese producers with cheap local styrene and anhydrides are lowest cost. Indian and Southeast Asian makers buy imported styrene and PG at CFR parity. Freight and shelf life limit how far resin can travel, so regional producers survive.

Raw materials on the commodity table

Oil Crude oil

What it is made into

Product	Note
Pnt Paints and coatings	gelcoats, putties and some wood coatings (small)