Polymer Additives Introductions Thermo plastics materials are processed

Polymer Additives Introductions Ø Thermo plastics materials are processed in the melt at high temperature & under high shear. Ø During their service life the final products have to service severe exposure to conditions such as heat , light & humidity , without changes in appearance or premature mechanical failure , in some case for several decades. Ø For avoiding those failure & getting few many different properties like antistatic , flammability etc. . , Ø Additives are ingredients added to polymers in order to obtain or improve certain properties such as strength, stiffness, color, resistance to weather and flammability. Chapter 15 -

Technology requirements Chapter 15 - 2

Continue…. o Change the properties of plastic materials o Enlarge the field of application drastically o Protect your plastic against alteration and degradation o Help to meet the recycling requirements o Extend the lifetime of product o Differentiate with others Chapter 15 - 3

Plastics Additives Chapter 15 - 4

Classifications of Additives Plastic Additives to modify plastics effect Properties by physical means reactions Plasticizer Lubricants Impact modifiers Fillers Pigments, etc. Additives achieve their by chemical Heat stabilizers Antioxidants UV absorbers Flammable Retardants Chapter 15 -

Examples…… Ø Fillers – ex: carbon black, silica gel, wood flour, glass, limestone, talc, etc. Ø Plasticizers – Ex: Phthalate , Trimellitates , Aliphatic dibasic esters etc. Ø Stabilizers 1. Antioxidants(Ex: Hydroxyphenylpropionates , Thioesters ) 2. UV stabilizers(Ex: 2 -Hydroxybenzophenones ) Ø Lubricants – Ex: Na stearate Chapter 15 - 6

Continue…. . Ø Colorants –Ex: Titanium dioxide Ø Slip & Anti-block agents –Ex: Calcium carbonate Ø Blowing Agents –Ex: Pentane , Heptane Ø Flame Retardants – Ex: Aluminium trihydrade Chapter 15 -

Requirements for Selection Ø Should be efficient in their function. Ø service conditions. Ø Should not bleed or bloom. Ø Should be non-toxic and should not impart taste or odour. Ø Should not adversely affect the properties of the polymers. Ø Should be cheap. Chapter 15 - 8