Introduction
DSM Composite Resins is a leading producer of Unsaturated Polyesters Resins. Stamicarbon offers technology and product know-how for the commercial production of a broad portfolio of unsaturated polyester resins for various applications and end-markets (e.g. building & construction, automotive and marine industry).
Applications
Unsaturated polyester resins are used in the production of fiber reinforced plastics or non-reinforced filled products. Due to the ease and freedom of processing, Unsaturated Polyester Resins can be applied in the manufacturing of small and very large structures. We have a wide experience in application technologies or techniques like hand lay-up, spray-up, filament winding, relining, casting, pultrusion resin transfer moulding, vacuum injection techniques and closed mould technology SMC (sheet moulding compound) and BMC (bulk moulding compound). For more information regarding our product portfolio, please refer to our resin selector guide.
Benefits
Key benefits of DSM Unsaturated Polyester Resins technology are:
- State-of-the art, innovative proven process, product and application technology
- Wide variety of Unsaturated Polyester Resins portfolio for wide range of applications
- Well experienced in technology transfer
Technical details
The chemistry principles of resin synthesis are simple. First, an acid and a glycol react to form an ester.
| HOOCHC=CHCOOH |
+ |
HOCH2CH2OH |
-> |
HOOCHC=CHCOOCH2CH2OH + H2O |
| maleic acid |
+ |
ethyleneglycol |
-> |
ester + water |
The acid group (COOH) reacts with the OH group to form an ester and a water molecule. There are still two reactive groups on both sides of the ester chain. These can react with other groups to form a longer chain, whose end-groups can react with other groups to form an even longer chain, and so on. In this way a long chain can be formed, a polyester.
+ acid + glycol + acid + glycol +... -> ...acidglycolacidglycol... + n water
This reaction takes place at about 200°C, which allows the water to evaporate. The reaction will rapidly increase the viscosity due to the growth of the chains. At a carefully chosen point, the reaction is halted by cooling down the mixture. The polyester is diluted to styrene and additives (for controlling the curing process, color etc.) are added.
Why use styrene as a diluent? Because, like the maleic acid component, it contains a double (i.e. unsaturated) bond. Hence the name unsaturated polyester resin. When a small amount of initiator is mixed with the resin, this will start a reaction between the double bonds of styrene and maleic acid. This reaction is called curing and will result in a product that has high strength properties in all directions.
Below, a general overview is given of the production process for Unsaturated Polyester Resins.
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Technology Portfolio 
