1. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home IDENTIFICATION OF PLASTICS VISHAL VERMA Technical Officer

2. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home When working with plastics there is often a need to identify which particular plastic material has been used for a given product. This is essential to get an idea of the cost and likely properties of the product. The identification of plastics is generally very difficult due to: The wide range of basic polymers that is available for use. The wide range of additives that can be used to modify the properties of the basic polymer. The wide range of mixtures or compounds of polymers that can be manufactured to get the required properties. Despite this there are some simple tests that can be carried out to get a basic idea of the possible base polymer used for the manufacture of any given product. IDENTIFICATION

3. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONTENTS Introduction Simple method cutting test hot wire penetration test flotation test bending test dropping test Burning test Pyrolysis test Specific gravity test Solubility test Softening and Melting point Elemental Analysis Confirmation test

4. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home IDENTIFICATION BY SIMPLE METHOD Stage 1: Look at the sample This will give you a lot of information. The colour of the plastic will give you some information. Some polymers have restricted colour ranges, particularly the thermosetting types. Others tend to be glossier in colour (polypropylene), whereas some are both glossy and glassy (the acrylics). Stage 2: Feel the sample After you have carried out the tests in the is series a few times you will start to get the feel for various plastics. The polyolefins have a very distinctive feel and you can generally tell if it is one of them. The presence of glass fibre or other reinforcement materials can alter the feel and stiffness of the sample but you can sometimes tell by the feel if there is reinforcement present. Stage 3: Cut a thin sliver from the edge of the sample Cut a small sliver off the sample. This tells you a lot about the type of plastic you are trying to identify

5. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CUTTING TESTS If a shaving can be pared off with knife, it may be a thermoplastic. Note: PMMA and Polystyrene are brittle and difficult to pare If the material is rigid and will not pare off instead flakes of powders, it may probably a thermoset plastic. Scuff the sample with your fingernail. Results Scuffs with fingernail - Urea formaldehyde resin. Does not scuff with fingernail - Melamine formaldehyde resin.

6. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home HOT ROD PENETRATION TEST Heat an electronic soldering iron to red hot and press against the unknown sample. If the plastic material softens, and the rod penetrates the sample is thermoplastic. If the plastic material does not soften and the rod does not penetrate, the sample is thermoset plastic.

7. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home FLOTATION TEST This test will give the idea to distinguish the material according to their density. Note:Filled polyolefin’s and cellular foams are exceptional for this test. Floats on type of plastics AlcoholVegetable oilwaterglycerin PETNo HDPENo Yes PVCNo LDPEYesNoYes PPYes PSNo Yes

8. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home BENDING TESTS Some plastics will exhibit particular characteristics in the manner in which they respond to bending. The bending behaviour of some plastics are given in Table PLASTICSBENDING BEHAVIOUR 1.PolyethyleneBends, tends to remain 2.PolypropyleneUnbends most of the way 3.PolystyreneCracks but retains bend 4.ABSBend tends to remain 5.PVC (Rigid)Bends easily and springs back quickly 6.Cellulose acetateBend tends to remain 7.PMMACracks and splinters 8.NylonDifficult to bend, springs back 9.PolycarbonateTough to bend

9. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home DROPPING TEST When a polymer moulded component is dropped on hard surface, it creates sound, which shall be either metallic sound or dull sound. On the basis of sound polymer is distinguished in two categories, which is tabulated in Table Metallic sounddull sound PS, HIPSCellulosics SAN, ABSPolyamides PC, PPSPTFE, PMMA PPOPolyacetal PolysulphonePVC, Polyolefins

10. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home BURNING TEST A small sample is held in flame. If it ignites withdraw it from the flame a distance of flame. Make observations as listed below and record the observations, for example: Degree of flammabilityburns Self extinguishingdoes not burn Colour of flameyellow and orange; Blue; blue with yellow edges; clear, Type of flamesteady; tall; short; sputtering Smokenone, black, thin and thick black with sooty streamers Melt behavioursoftens remains hard; flows; bubbles; swells; does not char but melts; melts and chars OdourBurning rubber; sweet – fruity; marigolds; burning paper; acid; rancid butter

11. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Typical results of burning tests of polymers (thermoplastics ) ThermoplasticsMelting BehaviourColour of Flame/ kind of smoke Odour / smell PEMelt and bubbles fiercely around the edge, Drips Blue base with yellow tip Waxy (Burning Candle) PPBecomes soft, tends to form a ball, Drips Blue base with yellow tip Lubricating oil smell PTFEDoes not melt, self – Extinguishing Will not burnNone PS / SANMelts and bubbles around the edge, spurting, burns readily Orange – Yellow, Heavy, Black, Sooty Smoke Mari gold, Strong smell of Styrene and Burning rubber High Impact poly styrene Melts and bubbles around the edge, spurting, burns readily Orange – Yellow, Heavy, Black, Sooty Smoke Slight burning rubber smell ABSBecomes soft but not fluidOrange – Yellow, Heavy, Black, Sooty Slight burning rubber smell PVCSoften and forms a ball, chars at bottom, self – Extinguishing Yellow with green bottom edge, Some White Smoke Chlorine smell, pungent

12. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Typical results of burning tests of polymers (thermoplastics) cont. Thermo plastics Melting BehaviourColour of Flame/ kind of smoke Odour / smell CAMelts and emits white smoke boils and chars Yellow, burns brown at base, Some light Smoke Smell of Vinegar (Acetic acid) CNMelts and emits white smoke – Burn Furiously, dangerous Hot, WhiteCamphor (Mothball) CABMelts and Char at the edge, dripsDark yellow with light blue base, Some light black Smoke Rancid butter (an Odour of butyric acid) PMMABoils and BubblesBlue and Yellow Flame, Some light black Smoke Fruity, Floral smell PCMelt but chars, Bubbles develops a cellular structure before decomposing, self – Extinguishing Orange yellow flame with black smoke Phenolic smell ( ink smell) PPOMelt but chars, self – ExtinguishingOrange yellow flame with black smoke Phenolic smell ( ink smell) NylonMelts round edges and chars, Froth formation and drips Blue with Yellow tipBurning hair / wool / vegetarian

13. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Typical results of burning tests of polymers (thermoplastics ) cont. Thermo plastics Melting BehaviourColour of Flame/ kind of smoke Odour / smell AcetalMelts, forms drops, Burns readily Pale bluePungent smell of Formaldehyde PET/ PBTMelts, opacifies, blackens, Molten Material drips Yellow, Slightly smokyPleasant elusive odour Polyvinyl Acetate SoftensDark Yellow, Spurts with black smoke Vinyl acetate smell (Sweet odour) CaseinSwells and chars on ignition, Self – Extenguishing, Yellow, Grey smokeBurning milk Poly phenylene sulphide Melt and char, self extinguish Orange yellow flame with black smoke H2S smell or rotten egg smell PUDrip like oil Blue base yellow tip burns continuously, no smokeYellow flame, black smoke Faint apple smell or castor oil smellFiant apple smell or castor oil smell

14. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Typical results of burning tests of polymers (thermoset) ThermosetColour of Flame/ kind of smokeOdour/ smell Phenol ResinYellow flame, self extinguishing, Some sparks Charcoal smell Urea ResinYellow with light blue edge, self extinguishing Fishy smell Melamine ResinYellow with light blue edge, self extinguishing Fishy smell Polyester Resin (Unsaturated) Burn with orange yellow flame, Black smoke Ester smell EpoxyYellow flame, Black smokeCharred flour smell

15. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Typical results of burning tests of polymers (Elastomer) ElastomerColour of flame/ smoke Flame & kind of smoke Odour/ smellOther notable characteristics Poly butyleneYellow, blue base SmokyDisagreeable, SweetChars readily Styrene - butadieneBurns continuously Yellow sooty Pungent smell of styreneChars readily, dry powdery Ethylene propylene dienemer (EPDM) Burns continuously no smoke, blue base yellow tip Waxy smellDry powdery NBRYellow sootyUnpleasantTacky Butile rubber (IIR)Smoke free, candle likeHydrocarbon smellMelt does not char readily, tacky Polyisoprene (NR)Yellow sootyPungent like burn rubberChars & crack Polychloroprene (CR)Self extinguishing Yellow & smoky Pungent smell of chlorine Strongly acidic fumes, black residue dry powdery Silicone rubberBurns continuously, glow with white smoke powdery No odourDry white powdery

16. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home PYROLYSIS TESTS In this testing, heat few milligrams of the sample in an ignition tube and test the pyrolytic vapour with a moistened indicator paper. The behaviour of vapour to indicator paper is given as follows: ACID:turns blue litmus to red BASIC:turns red litmus to blue. ACID VAPOURS: may come from carbohydrate polymers & their derivatives. [e.g., cellulose acetate] HIGH ACID VAPOURS: often indicates the presence of chlorine. e.g., PVC or rubber neutral vapors] evolved from hydro carbon polymers, silicones and some polyesters hydrochloride. ALKALINE VAPOURS: indicate the presence of N2. e.g. polyamide, proteins & amino formaldehyde resins.

17. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home SPECIFIC GRAVITY TEST A simple test for differentiating between different types of plastics can be carried out by placing specimens in water. Some will sink and some will float depending on their specific gravity as shown in Table. Those with the higher specific gravities will sink as shown in the Table. Accurate specific gravity results can be obtained by the standard method of relating weight of the material to weight of water displaced. Floats in water (S.G. 1)Specific Gravity ≤ 1 PP0.90 LDPE0.92 HDPE0.96 Sink in Water floats in Hypo 1 ≤ Specific Gravity ≤ 1.1 PS1.07 SAN1.1 ABS1.1 NYLON1.1 Sinks in HypoSpecific Gravity ≥ 1.1 PMMA1.2 PMMA1.2 CA1.3 PVC1.4 ACETAL RESIN1.4 UREA RESIN1.5 PTFE2.75

18. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home SOLUBILITY TESTS Solubility tests form a basis of some older identification schemes for main types of plastic materials. However, in many cases solubility varies considerably for different samples of the same resin and it is difficult to interpret the results Solubility of plastics may vary according to the grade or to the whether or not other constituents are present in the sample. The data in Table refer in principle to pure polymers, although even those polymers may exhibit differences in solubility. The solubility test should be carried out directly in a test tube. To about 100 mg of a powdered sample add 10ml of solvent, mix occasionally shake the contents of the test tube and observe for a few hours swelling may occur before complete dissolution of the polymer.

19. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home PLASTIC MATERIALSOLVENTS Cellulose estersKetones, esters Poly (vinyl chloride)Dimethylformemide, tetrahydrofuran, cyclohexenone ABSMethylene chloride Vinyl chloride / Vinyl acetateMethylene chloride, cyclohexanone, tetrahydrofuran PolytetrafluoroethyleneFluorocarbon oil e.g. C 21 F 44 {hot) PolyacrylonitrileDimethylformamide, butyrolactone, nitrohenel, mineral acids, dimethylsulphoxide, aqueous solutions of some inorganic salts. Poly (Methacrylic acidesters)Arimatic hydrocarbons dioxen, chlorinated hydracarbons, esters, ketones. PolyamidesPhenols, formic acid, tetrafluoropropanel, conc. Mineral acids. Poly (vinyl acetal)Esters, Retones, tetrahydro – furan Poly (vinyl alcohol)Formamide water PolycarbonatesChlorinated hydrocarbons, dioxan, cyclohexanene. Polyesters, unsaturatedKetenes, styrene, acrylic esters. PolyethyleneDichloroethylens, tetralin, hot hydrocarbons PolyformaldehydeHot selvantas phenels, benzyl alcohol, dimethylformide. PolypropyleneAt elavator temp, aromatic and chlorinated hydrocarbons, tetralin PolystyreneAromatic and chlorinated hydrocarbons, pyridinc, ethylacetate, methylethyl ketone, diovan totralin.

20. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home SOFTENING AND MELTING POINTS The temperature range of softening and melting – point can be used to characterize/ identify the material. Procedure: Place the 2 to 3 mg portion on a clean glass slide and cover with No 1 cover glass. Heat the slide, sample and cover on a hot plate to slightly above the softening point of the polymer so that a thin film can be formed. By slightly pressure on the cover glass form a thin film 0.01 to 0.04 mm, and allow it to cool slowly by turning of the hot plate power to promote crystallization. Keep the slide on hot plate melting point apparatus. Adjust the hot plate temperature about 10 deg C below the melting point of sample. Then adjust the temperature ramp at 0.5 deg C/ min. observe the sample through microscope and note down the temperature where the material starts melting.

21. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Melting and softening point of polymer materials

22. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Tests for Polyolefins A piece of dry sample is pyrolysed in a tube closed with a filter paper which is drenched with a solution of 0.5 g yellow mercury (II) oxide in sulphuric acid (1.5 ml conc. Sulphuric acid added to 8 ml. Water). If the vapour gives a golden yellow spot, indicates polyisobutylene, butyl rubber and polypropylene (the latter only after a few minutes). Polyethylene does not react. Natural and nitrile rubber, as well as polybutadiene yield a brown spot.

23. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Chlorine containing polymers Cont. Copper wire test Take the piece of copper wire about 5 mm long. Push on end of the wire in to a small cork. Place one pellet or plastics sample near your Bunsen burner. This is the sample you will be testing. Hold the free end of the copper wire in the burner flame until it is red-hot and the flame no longer has a green colour. Remove the wire from the flame and torch the hot wire to the plastics pellet or sample you will be testing. A small amount of the plastics should melt onto the wire. Place the end of the wire, with small amount of plastic on it, into the flame. You should see a slight flash of a luminous flame (a yellow- orange colour). If the flame turns green in colour, then the sample contains chlorine.

24. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Caprolactum in Nylon 6 About 0.5 gm of sample is heated in 5.0 ml of distilled water and allowed to boil for 10 to 15 min. After cooling, 2-3 drops of con. H 2 SO 4 is added to 0.5 ml of the above solution followed by addition of 2 ml. of potassium iodo bismuthate ( a solution of 5 gm. of basic bismuth nitrate and 25 gm. of potassium iodide in 10 ml. of 2% H 2 SO 4 ). Precipitation of an orange red complex indicates the presence of caprolactum. Cont.

25. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Adipic acid in Nylon 6,6 About 0.2 gm of sample is heated in low flame in a test tube and the vapour coming out of the tube is passed over a filter paper moistened with a saturated solution of O- nitrobenzaldehyde in 2N aqueous NaOH. A deep violet colour confirms the presence of adipic acid. A yellowish green colour develops in the case of polyethylene-terephthalate and polybutylene-terephthalate confirming the presence of terephthalic acid. Cont.

26. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Polycarbonate About 1.0 gm of sample is pyrolysed in an ignition tube, which is plugged with cotton. The cotton is removed and immersed in 1% methanolic solution of p-dimethylamino benzaldehyde and then one drop of 5 N-Hydrochloric acid is added. A dark blue colour appears in the case of polycarbonates. A red colour that does not change to blue is observed in the case of polyamides. The cotton floak in which the prolysed vapours of the sample absorbed is treated with dilute (1:1) HCI. An intense red colour which is unaffected by methanol, indicates the presence of polycarbonate. Cont.

27. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for PMMA About 1 gm of sample is heated in an ignition tube and the pyrolysate is collected in a test tube wrapped with a wet filter paper. To the distillate, 1 ml. of conc. HNO3 is added and heated just to boiling. After cooling, 5 ml. of water is added an then sodium nitrite (0.1 gm) is added. A blueish green colour confirms the presence of polymethylmethacrylate. Cont.

28. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Polyacetals Polyacetals produce formaldehyde on heating. A small amount of sample is heated with 2 ml. conc. Sulphuric acid and a few crystals of chromotropic acid for about 10 min at 60 -70  C. A strong violet colour indicates formaldehyde. Cont.

29. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Tests for PET and PBT PET and PBT are soluble in nitrobenzene. A small sample is pyrolysed in a glass tube covered with filter paper. The filter paper is drenched with a saturated solution of O- nitrobenzaldehyde in dilute sodium hydroxide. A blue- green colour, which is stable against dilute hydrochloric acid, indicates terephthalic acid. Then PET and PBT are differentiated based on melting points. Cont.

30. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for polyurethane About 0.5 gm of sample is dissolved in 10 ml of glacial acetic acid and 0.1 gm of p-dimethylamino benzaldehyde is added. The solution turning yellow after several minutes shows the presence of polyurethane. Cont.

31. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Test for Cellulose Ethers: The important cellulose ethers are Methyl cellulose, Ethyl. Cellulose and Benzyl cellulose. Reaction to Heating and Burning: Cellulose ethers melt and char after heating and continuously burn after ignition. Nature of flame and smell of the cellulose ethers are as follows: Cont. Methyl celluloseBrilliant yellow flameOdour of burnt paper Ethyl celluloseless brilliant flame accompanied by dripping Benzyl celluloseBrilliant sooty flame smells like bitter almonds

32. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Polyvinyl Alcohol A Sample (about 0.02g) is dissolved in water 5ml and iodine reagent described above (5 drops) added. The formation of Blue colour confirms the presence of Polyvinyl alcohol. Cont.

33. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Casein A sample about (0.02g) is dissolved in concentrated HNO 3 (2ml) by boiling for about 5mn. The solution is cooled and excess 5N ammonium hydroxide added. The formation of orange colour confirms the presence of casein. Cont.

34. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - Thermoplastics Shellac A sample (0.05g) is dissolved in ethanol (1ml) with warming. To the cooled solution is added water (about 1ml) to give an emulsion like precipitate. 5N aqueous NaOH 2 drops is added to the mixture. The colour change is reversed on acidification with 5N HCL. The formation of Violet - red colour confirms the presence of Shellac. Cont.

35. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - THERMOSET PLASTICS Test for formaldehyde A small amount of sample is boiled in water in presence of H 2 SO 4 and filtered. Few drops of 5% aqueous chromotropic acid solution (1,8-dihydroxynaphthalene-3, 6-disulphonic acid) and excess of cone. H 2 SO 4 are added to the filterate and heated at 1000 C for few minutes. In the presence of formaldehyde, the solution turns violet/dark violet. Poly (vinyl formal), polyoxymethylenes, PF, UF and MF resins contain formaldehyde.

36. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - THERMOSET PLASTICS Test for Phenol in PF Million's Reagent: About 10 gm of Hg is dissolved in 10 ml. of HNO 3 by gentle heating and then diluted with 15 ml. of distilled water. The sample is heated to boiling for two minutes with 1 ml. of clear million's reagent. Red colour indicates the presence of phenol in the sample. Cont.

37. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - THERMOSET PLASTICS Test for Urea in UF About 0.5 gm. of sample is refluxed for 30 min. with 20% acetic acid (50 mI.). The mixture is cooled and filtered. To the filterate added a solution of (2 ml.) xanthydrol in methanol (1% solution) and boiled for 1-2 minutes. White bulky precipitate confirms the presence of urea. Cont.

38. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - THERMOSET PLASTICS Test for Melamine in MF About 0.5 gm of sample is refluxed with 80% acetic acid (25 ml.) for 30 min., cooled and filtered. Then the filterate is evaporated to dryness and added 2 ml. of water, cooled and filtered. To the filtrate one drop of saturated aqueous picric acid is added. Yellow precipitate indicates the presence of melamine. Cont.

39. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home CONFIRMATION TEST - THERMOSET PLASTICS Tests for Epoxy Resin Foucry Test: About 0.25 gm. of sample is dissolved in 98% H 2 SO 4 by slight warming. After cooling 1 ml. of 63% HNO 3 is added. After shaking, the mixture is poured into 100 ml. of 5% aqueous NaOH. A bright red or orange red colour indicates the presence of epoxy resin. Cont.

40. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Rubber Testing: For identification of CR, NBR, SBR, NR / IR, IIR type of rubbers Test Procedure: Heat strongly 0.5gm of sample in a test tube until sample begins to decompose and pass the fume in solution II and I and observe change in colour initially and after heating. (Refer the following table) Solution - I : Dissolve one gram of p - dimethyl amino benzaldehyde in 5ml of HCl and add 10ml of ethylene glycol. Adjust the density to 0.851 gm /cc. by addition of methanol. Solution - II : Dissolve 2gm sodium citrate, 200mg of citric acid, 300mg of bromo cresol green and 300mg of metanil yellow in 500ml of water. RUBBERSolution - ISolution II InitialAfter Heating Blank SolutionPale Yellow Green CRYellowPale Yellow GreenRed NBROrange RedRedGreen SBRYellow GreenGreen NR / IRBrownViolet BlueGreen IIRYellow Droplet FloatsPale Blue GreenGreen

41. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home Identification code of plastics

42. CENTRAL INSTITUTE OF PLASTICS ENGINEERING AND TECHNOLOGY, CHENNAI IDENTIFICATION OF PLASTICS Home