Additives are today intensively used in the plastic industry to provide materials different properties or protection (Stabilisation, Flame retardant, reinforcement…). Additives are generally small organic molecules or minerals introduced at low levels like stabilizers or surface modifiers. For reinforcement or flame retardant higher loading is required particularly for halogen free FR systems containing in some cases more than 60wt% of additive.
Polymers introduced at low levels in formulations (Less than 10%) can significantly modify or improve properties like an additive does. The polymeric nature of the additives can provide particular benefits like impact modification, surface modification>, low migration additives. The aim of this paper is to give an overview of different polymers used as additives and modifiers in thermoplastics.
In most cases, polymers are not miscible together and when they are mixed, we observe a dispersion of the minor phase (dispersed phase) in the major one (matrix). This phenomena offer many possibilities of modification, properties adjustment and surface modification needed to serve customers needs.