Styrene Based Polymers Styrenics Introduction of polystyrene Monomer

Styrene Based Polymers (Styrenics) Introduction of polystyrene Monomer preparation Polymerization Mass polymerization Suspension polymerization Solution polymerization Available grades Properties related to structure General properties Processing behaviour Processing techniques Applications CORPORATE TRAINING AND PLANNING

High impact Polystyrene (HIPS) Introduction General properties Applications Acrylonitrile butadiene styrene (ABS) Introduction Preparation of ABS Properties of ABS Processing behaviour Processing techniques Applications Styrene acrylonitile (SAN) Introduction Properties of SAN Applications CORPORATE TRAINING AND PLANNING

Polystyrene Introduction mercially duced y first Polystyrene was Ø Dow chemical company in 1937. Ø Polystyrene was first initially used for its excellent dielectric and optical properties. CORPORATE TRAINING AND PLANNING

Monomer Preparation Ø Styrene is produced from the ethyl-benzene by a process of dehydrogenation at 630°C. CORPORATE TRAINING AND PLANNING

Ø Styrene at room temperature is a liquid with boiling point at 145. 2°C. aromatic many Ø pleasant Like compounds, smell has it in pure form but looses the same due to traces of ketones and aldehydes if allowed to oxidize by exposure to air. Ø Ø rubbers, including SBR, but has only a very limited mutual solubility in water. on exposure to UV light. CORPORATE TRAINING AND PLANNING

Polymerization methods Ø Ø Ø Mass Suspension Solution CORPORATE TRAINING AND PLANNING

Mass Polymerization (Tower Process) Ø Styrene is pre-polymerized by heating (without initiators) at 80°C for two days in pre-polymerization kettle. Ø Monomer-polymer mixture is then run into a tower which is fitted with heating and cooling jackets and the top of the tower is maintained at temperature of 110°C, the temperature of about 150°C in between and bottom temperature at 180°C. Ø High temperature at bottom ensures a high conversion. Ø Base of the tower forms the hopper of an extruder from which melt emerges as filament which are cooled, disintegrated and packed. CORPORATE TRAINING AND PLANNING

Solution Polymerization Ø Ø through number of reactors with different heating zones. vessel. temperature Ø a 225°C, At solvent polymer of the and are removed, condensed and polymer is fed into extruder units, extruded as filaments, granulated, and stored. n Ø lead to problem of solvent recovery and solvent hazards. CORPORATE TRAINING AND PLANNING

Suspension Polymerization Ø Ø Ø uantity resulting of the The depends particle size on Ø In this process the monomer is suspended in droplets. such as Benzoyl peroxide. suspension agents e. g. Poly (vinyl alcohol), talc to prevent them cohering. suspension agent and speed of agitation. polymerization, Following may monomer unreacted Ø removed by steam distillation and the polymer is washed and dried. CORPORATE TRAINING AND PLANNING

Structure Property Relationship Ø PS is linear hydrocarbon polymer. Ø Due to steric hindrance of benzene ring causing stiffening effect, the Tg. of commercial polymer is 90° to 110°C. Consequence of this Tg value and amorphous nature of material make it hard and transparent at room temperature. Ø It is soluble in benzene, styrene, toluene. The presence of benzene ring in polystyrene having greater reactivity than Polyethylene. Ø Due to phenyl group Polystyrene is having limited chemical resistance. CORPORATE TRAINING AND PLANNING

General properties of PS 1. General properties of Polystyrene are, 2. Hard, rigid and transparent thermoplastic. 3. Low cost, good mouldability. 4. Low water absorption, good dimensional stability. 5. Good electrical insulation properties, colourability. 6. cyclic amines or aminoalcohols has been found to improve greatly the resistance to weathering. 7. It is brittle in nature. 8. water. 9. It is having mediocre oil resistance. CORPORATE TRAINING AND PLANNING

Properties of Polystyrene Name Value Unit Specific gravity 1. 05 -- Tensile Strength 32. 4 -56. 5 MPa Tensile modulus 3103 -3276 MPa Flexural modulus 3103 -3448 MPa Elongation at break 1. 2 -3. 6 % Impact Strength (Izod ) 13. 3 -24 J/m Hardness M 60 -84 --- HDT (under 1. 82 MPa load. ) 76 -108 °C Glass transition temperature 74 -110 °C Dielectric Strength 19. 7 KV/mm CORPORATE TRAINING AND PLANNING

Processing Considerations des nmodified 1. absorption. 2. 3. plasticizing capacity machines should be used. Melts have good stability at processing temperatures. 4. Generally no need to purge while shutting down. 15 -20% than 5. Recycling more percentage be should not in injection moulding. Due 6. shrinkage. 7. CORPORATE TRAINING AND PLANNING

Processing Techniques Injection Moulding Ø Plastic temperature in the process range from 200° C to 250°C for GPPS and 180° to 250°C for HIPS grades. Ø Injection pressures are of 30 to 275 MPa depends on the grade of the material. Ø Typical mould temperature is 10 -80°C. CORPORATE TRAINING AND PLANNING

Extrusion Ø Typical extrusion conditions Temperature profile 150 -200°C Recommended screw L/D ratio 25: 1 to 30: 1 Recommended compression ratio 2: 1 to 3: 1 CORPORATE TRAINING AND PLANNING

Grading of Polystyrene Ø General purpose polystyrene (GPPS) Good balance is maintained to have good heat resistance, reasonably high setting-up temperature, good flow properties and moderate impact strength. Ø High molecular weight polystyrene (HMPS) HMPS gives impact strength without the loss of clarity. Ø Heat resistant grade By reducing monomer content from 5% to 0%, softening point may raised from 70°C to 100°C. Ø Easy flow grade It can be obtained by using low molecular material, by using internal lubricant , by using external lubricant and by controlling size and shape of granules. CORPORATE TRAINING AND PLANNING

Trade names Supreme, India – Suprene Dow Chemical, US – Pelaspan Arco chemical , US – Dylene Kanegafuchi chemical, Japan - Kanelite CORPORATE TRAINING AND PLANNING

Expanded Polystyrene Suspension )Polymerization Bead Ø for manufacturing expanded polystyrene. Ø polymerization or used to impregnate the bead under heat and pressure in a post-polymerization operation. Ø impregnated T he processed beads may then be two by basically different techniques. Ø Steam moulding process. Ø Direct injection moulding or extrusion. Ø previous size with densities as low as 16 kg / cm 3. CORPORATE TRAINING AND PLANNING

Applications of PS Household Ø CORPORATE TRAINING AND PLANNING

Ø Medical applications like disposable syringe. Packaging Ø CORPORATE TRAINING AND PLANNING

Applications PS Room Partitioner PS Door fittings PS Bathroom cell CD cover CORPORATE TRAINING AND PLANNING

Ø Ø Ø High Impact Polystyrene (HIPS) styrene monomer and polymerizing the monomer in a solution or mass-suspension process. The rubber is generally polybutadiene. rubber and polystyrene but also a graft polymer where short styrene side chains have been attached to the rubber molecules and this enhances the impact strength. solution rubber Øcontent The polymerization in up go can to 14% by weight. S Ø times greater than GPPS. CORPORATE TRAINING AND PLANNING

General Properties Ø Good dimensional stability even at low temperature and high impact strength than the general purpose polystyrene. Ø to stress cracking. Ø GPPS. Ø by alcohols, ketones, ethers etc. CORPORATE TRAINING AND PLANNING

Properties of HIPS Name Value Unit Specific gravity 1. 05 -- Tensile Strength 16. 0 -41. 3 Mpa Tensile modulus 1653 -2549 Mpa Flexural modulus 1791 -2687 Mpa Elongation at break 1. 0 -1. 5 % Impact Strength (Izod ) 48. 1 -219 J/m Hardness M 63 -88 --- HDT (under 1. 82 MPa load. ) 69 -76 Glass transition temperature 93 -105 °C Dielectric Strength KV/mm 11. 8 -19. 7 CORPORATE TRAINING AND PLANNING °C

Processing of HIPS Thermoforming Ø Ø Ø orming erature e Typical Ø Solid sheet of HIPS is extruded and shaped by a variety of forming methods. The most common method is in-line vacuum forming. mold or pressure is applied to the mold plug while air is drawn out from the space the sheet and mold. 180°C and temperature at which forming may be removed from the mould is at 85°C. CORPORATE TRAINING AND PLANNING

Applications of HIPS Household Ø CORPORATE TRAINING AND PLANNING

Applications HIPS Instrument body HIPS Television Cabinet HIPS Solid shape HIPS Floppy Storage Box CORPORATE TRAINING AND PLANNING

Acrylonitrile Butadiene Styrene (ABS) Copolymer Ø CORPORATE TRAINING AND PLANNING

ABS Preparation 1. CORPORATE TRAINING AND PLANNING

General Properties 1. 2. 3. Chemical and Solvent resistance Generally resistant to alkalis and acids but not concentrated oxidizing acids. Dissolved by many aromatic and chlorinated hydrocarbons, esters and ketones. 4. 5. 6. Maximum Service temperature UL temperature index 60 -75°C. Alloy with Polycarbonate may be as high as 95°C. 7. 8. Flammability Standard grades are considered as slow burning and usually meet the UL HB requirement. The material burns with a smoky yellow flame emitting a pungent gas. 9. CORPORATE TRAINING AND PLANNING

Properties of ABS Properties Specific gravity Tensile Strength Tensile modulus Flexural modulus Elongation at break Impact Strength (Izod ) Hardness HDT (under 1. 82 MPa load. ) Glass transition temperature Dielectric Strength Value 1. 03 -1. 06 30 -52 2070 -2760 2200 -3030 2. 3 -3. 5 134 -320 R 105 -112 93 -104 105 -115 16 -31 CORPORATE TRAINING AND PLANNING Unit -MPa MPa % J/m --°C °C KV/mm

Processing Considerations Ø CORPORATE TRAINING AND PLANNING

Processing Techniques Injection Moulding Typical Injection Moulding conditions Ø Recommended melt temperatures 220 -280 °C. Ø Typical mould temperature is 40– 90 °C. Ø Injection pressures of 69 -138 MPa. Ø L/D ratio is 20: 1 and Compression ratio of 2: 1 to 3: 1. CORPORATE TRAINING AND PLANNING

Extrusion Typical extrusion conditions Ø Melt temperatures 205 -250 °C. Ø Temperature profile 192 -250°C. Ø Recommended screw L/D ratio 20: 1 to 36: 1. Ø Recommended Compression ratio 2. 5: 1 to 3: 1. CORPORATE TRAINING AND PLANNING

Thermoforming Ø CORPORATE TRAINING AND PLANNING

Electroplating Ø ABS is the best material for electroplating. olymer The Ø dissolves out some of the rubber particles at or near the polymer surface. After sensitization and activation electroless metal deposition processes are carried out. CORPORATE TRAINING AND PLANNING

Trade names GE, India Bhansali polymers , India Kanegafuchi chemical, Japan Bayer , DE Polychemical co, Taiwan - Cycolac - Abstron - Kane Ace - Novodur - Polylac CORPORATE TRAINING AND PLANNING

Applications of ABS Automobile Ø CORPORATE TRAINING AND PLANNING

1. 2. Household trucks, refrigerators liners, refrigerator door handles, pipe fittings, ventilator system components, picnic boxes, food processors, coffee maker leads, microwave oven tops. 3. 4. Medical CORPORATE TRAINING AND PLANNING

Applications ABS Car Dashboard ABS car interiors ABS Car bumper ABS meter box CORPORATE TRAINING AND PLANNING

Blends of ABS Ø ABS/PC Increase in HDT up to 130°C. Ø ABS/PVC (80: 20) Fire retarding ABS type material. Ø ABS/PVC (10: 90) Impact modified form of unplasticised PVC. Ø ABS/Acrylic material A reasonable transparent ABS-type polymer. CORPORATE TRAINING AND PLANNING

Styrene Acrylonitrile Copolymer (SAN) Ø SAN is a copolymer of styrene and acrylonitrile. CORPORATE TRAINING AND PLANNING

h The main features of SAN are, Ø Excellent dimensional stability. Ø Very good tensile and flexural strength. Ø Good abrasion resistance and impact strength. Ø cracking and crazing. Ø PS. CORPORATE TRAINING AND PLANNING

Grading of SAN - - UV stabilized grade Antistatic grade Glass reinforced grade CORPORATE TRAINING AND PLANNING

Properties of Styrene acrylonitrile Name Specific gravity Tensile Strength Tensile modulus Value 1. 07 57 -75 3420 -3720 Unit -MPa Flexural modulus Elongation at break Impact Strength (Izod ) Hardness HDT (under 1. 82 MPa load. ) Glass transition temperature Dielectric Strength 3080 -3560 2. 0 -3. 5 13 -24 M 80 -83 99 -109 115 12 -16 MPa % J/m --°C °C KV/mm CORPORATE TRAINING AND PLANNING

Applications SAN cassette casing SAN speedometer cover CORPORATE TRAINING AND PLANNING