Degradation, stabilization Introduction Degradation – Definitions, classification – Depolymerization – Elimination – Chain scission, cross-linking – Other degradation mechanisms Stabilization – PVC – Polyolefin Other additives – Lubricants – Pigments – Biostabilizers – Plasticizers – Nucleating agents – Peroxides, cross-linking – Chemical foamers – Impact modifiers – Fillers and reinforcing – Flame retardants

Degradation – root cause Thermal degradation Photo degradation Chemical degradation Radiation Mechanical degradation Biological decomposition More than one effect occur simultaneously

Depolymerization – effect of molecular structure b) Rate of gas evolution Temperature (C)

Elimination – mechanism, secondary reactions PVC Formation of rings

Chain scission – mechanism and cross-linking Initiation Termination Propagation oxidation, radical processes Branching

Chain scission, cross-linking – effect on properties

Other degradation mechanisms Ring formation – PAN (carbon fiber) Hydrolytic degradation Effect of Oxygen on the elastomers

Stabilization of PVC – requirements and classification Prevent of elimination of HCl (preventive stabilization) Decrease of the length of polyene sequences (correction stabilization) Classification Preventive stabilization – Binding HCl – Elimination of weak sites – Prevent autooxidation – The suppression of mechanochemical chain scission by internal processing aids Correction stabilization – Addition to the conjugated polyenes – Decomposition of carbonium salts

Stabilization of PVC – classification Metal soaps – Barium/Cadmium stabilizers – Barium/Zinc stabilizers – Calcium/Zinc soaps Lead stabilizers – Tribasic lead-sulphate – Dibasic lead-phosphit – Dibasic lead-phthalate – Dibasic lead stearate – Lead stearate – Dibasic lead carbonate Organic tin based stabilizers – Organic tin-mercaptides and sulphides – Tin carboxilates Metal free stabilizing agents – -aminocrotonic acid ester Co-stabilizers – Organic phosphites – Epoxy derivatives – epoxydated soioil – Polyols – pentaeritrit – Antioxidants – Other organic compounds – example: diketones

Stabilization of PVC Binding of HCl Substitution of non stable Cl atoms Addition to polyene

Stabilization of PVC – synergetic effect of stabilizing systems

Stabilization of PVC – example: window profile PVC (K value: 65-67) 100 mr Impact modifier (CPE) 6-8 Lead phosphite 2.0 Dibasic lead stearate 0.5-0.7 Neutral lead stearate Calcium stearate 1.0 Epoxydated oil Paraloid K 120 N (acrylate lubricant) 1.5 Titane-dioxide (white pigment) 4-6 CaCO3 (Filler) 10-20 Pigment variable

Stabilization of polyolefin – primary and secondary antioxidants Primary stabilization – phenolic antioxidants Secondary stabilization – phosphit

Stabilization of polyolefin – types of primary antioxidants Alkylphenols (a) Hydroxiphenol propionate (b) Hydroxibenzene compounds Alkylidene bisphenols Secondary aromatic amines Tiobisphenols Aminophenols a) b)

Stabilization of polyolefin – types of secondary antioxidants Tio-esters Phosphit and phosphonite Sterical hindered amines

Stabilization of polyolefin – photo stabilizers UV absorbent Hydroperoxide dissociators Radical consumers – hindered amines (HALS) Quvechers – compounds containing nickel – Ni phenolate

Stabilizator consumption Chemical modification Mechanical properties Stabilization of polyolefin – chemistry, structure and property correlations LDPE + O2 + stabilizator Stabilizator consumption Chemical modification Color Chain scission Recombination Molecular structure Homogeneity Orientation Processing Mechanical properties

Other additives – processing aids, issues, types, application Function Decrease of viscosity Decrease of heat generated from friction Decrease of cohesion Regulation of melting Flow anomalies (melt breaking) Influencing of surface quality Types Metal soaps Fatty acids and their esters Amide waxes Hydrocarbon waxes Ester waxes Lubricant (1000 t) Predominantly in PVC

Other additives – lubricants, types, application Compatibility Solubility Internal lubricants External lubricants Polar/non-polar ratio Mechanism Continuous transition Interaction

Other additives – pigments Organic pigments Optical whitener Biostabilizers – 10,10’-oxy-bis-fenox- arzin – N-(trihalogenomethyl- tio)-phthalimide – Diphenilstilbene-2-ethyl- hexanoát – Cu-bis-(8-hydroxykino- lin) – tributhyl tin and their derivatives

Other additives – plasticizers, application, types Plasticized polymers PVC PVDC – poly(vinylidene-chlorid) Poly(vinyl-butirate) Poly(vinyl-acetate) Polyacrylates Polyamide-12, other polyamides Cellulose derivatives Plasticizer types Amount (%) Phthalates 61 Phosphates 6 Adipates, sebacates 4 Polyesters 2 Fatty acid esters Epoxydated esters of fatty acids 5 Cyclic esters 14 Other plasticizers

Other additives – peroxides Hydroperoxides, R-O-O-H Alkyl peroxides, R1-O-O-R2 Peroxy esters, R1-CO-O-O-R2 Diacyl peroxides, R1-CO-O-O-CO-R2 Peroxychelates, R1-CO-O-O-R2 Application fields Wire insulation and protection Continuous profiles crosslinked in salt bath Tubes used in automotive cooling systems Boots Covering barrels Hollow articles made by rotational molding Medical tools, example pipes Integrated foams Dicumil-peroxide

Other additives – nucleating agents, foaming agents Nucleating agent - requirements Adsorption Solubility High melting point Dispersity Types Inorganic, example: talcum mono- és polycarboxylic acids and their esters Polymers and copolymers Topology Chemical foaming Azoderivatives Semicarbazides Tetrazol Benzoxazine azodicarbonamide

Other additives – Antistatic agent and impact modiliers Antistatic agents Protection agains charging Clothing Chemical industry Mining Fuel handling Detergents Glicerin-monostearate Fatty acid esters Alkyl amides Alkyl sulphonates Conductive fillers Impact modifiers a) PVC CPE EVA copolymer MMA/butadiene/Styrene copolymers Polyacrylates ABS copolymers b) Polypropylene EPR and EPDM copolymers c) Polystyrene SBS copolymers d) Topology modified EPDM modified polyethylene

Other additives – flame retardants Fillers and reinforcing materials Flame retardants Radical consumers Intumescent flame retardants attenuation, cooling Type Usage (1000 t) Polyolefin 11,0 PVC 26,0 Polystyrene and ABS 5,5 Engineering plastics 1,7 Unsaturated polyesters 7,8 Epoxy resins 3,7 Polyurethanes 12,8 Rubbers and elastomers Other polymers 11,6 Sum 85,6