A small amount of acrylate comonomers are routinely used in PMMA grades destined for heat processing, since this stabilizes the polymer to depolymerization ("unzipping") during processing. Comonomers such as butyl acrylate are often added to improve impact strength. Comonomers such as methacrylic acid can be added to increase the glass transition temperature of the polymer for higher temperature use such as in lighting applications. Plasticizers may be added to improve processing properties, lower the glass transition temperature, improve impact properties, and improve mechanical properties such as elastic modulus Dyes may be added to give color for decorative applications, or to protect against (or filter) UV light. Fillers may be substituted to reduce cost.
A smalL aMount of acRyLate COmONomERs aRE rOutinEly uSed in pmma gRades deStineD for hEAt procEssINg, since This stAbiliZeS tHE polYmer to depoLYMeRizATIon ("uNzipping") duriNG pRoceSSIng. comonomers such as bUtYl acrylatE aRe ofTen added To iMpRovE ImPacT strengtH. ComONOmeRs sucH as METHAcrylic acId cAN be aDDed tO increase the glass transItiOn TempeRaTure oF the pOlymer FOR hiGher teMpErAtuRe Use Such aS iN ligHTing APPLicatioNs. PlAsTIcIzers may be added To iMproVE ProcEssing proPertIes, loweR The glass TRansition TEmpErAture, impRovE impact proPertIes, AnD iMPROve MeCHanical pROPerTies sucH as elaStic ModuluS dyes mAy Be AddEd tO giVE cOlOR for decoRAtivE APpLicaTions, or To PRotECt AGaiNSt (or filter) uV Light. fIllers may be SuBstituTEd to REdUce cost.