May 11, 2024
Unsaturated polyester resins (UPRs) are versatile materials used in various industries, such as automotive, construction, marine, and aerospace. Additives are often incorporated into UPR formulations to enhance their performance, processing characteristics, and end-use properties. Some common additives used in unsaturated polyester resins include:
Fillers: Fillers are added to UPR formulations to improve mechanical properties, reduce cost, and control shrinkage. Common fillers include calcium carbonate, talc, silica, and glass microspheres.
Thickeners: Thickeners are used to adjust the viscosity of UPR formulations, facilitating better handling and application. Examples include fumed silica, colloidal silica, and clay-based thickeners.
Initiators: Initiators are compounds that initiate the polymerization reaction in UPR systems. Peresters, such as methyl ethyl ketone peroxide (MEKP), are commonly used initiators in combination with accelerators.
Accelerators: Accelerators are additives that increase the rate of polymerization in UPR systems. Cobalt and tertiary amines are commonly used accelerators in combination with peroxides.
Inhibitors: Inhibitors are added to UPR formulations to prevent premature polymerization during storage and transportation. Hydroquinone and tertiary butyl catechol (TBC) are commonly used inhibitors.
UV Stabilizers: UV stabilizers are incorporated into UPR formulations to protect the resin from degradation caused by exposure to ultraviolet (UV) radiation. Hindered amine light stabilizers (HALS) and benzophenone derivatives are commonly used UV stabilizers.
Colorants: Colorants are added to UPR formulations to achieve desired aesthetic properties. Pigments and dyes are commonly used colorants.
Modifiers: Modifiers are additives used to tailor the properties of UPR formulations, such as impact resistance, flexibility, and flame retardancy. Examples include reactive diluents, toughening agents, and flame retardant additives.
Release Agents: Release agents are used to facilitate the release of UPR products from molds during the curing process. Silicone-based and wax-based release agents are commonly used.
Anti-foaming Agents: Anti-foaming agents are added to UPR formulations to control foam formation during mixing and processing.
These additives are carefully selected and balanced to achieve the desired performance and properties in the final UPR product. The specific additives used can vary depending on the intended application and performance requirements of the resin system.
