1. ATR-ASSISTED ANALYSIS OF UNLABELED RECYCLABLES
Faria Nusrat and Maria Vogt
Division of Natural Sciences and Mathematics; Bloomfield College, Bloomfield, NJ 07003
U.S. Total Municipal Solid Waste
Generation in 2012
Common Plastic Resin Profiles with Characteristic IR Frequencies
Purpose
Acknowledgements
Metal/Glass/Paper to Plastic
Resin Type Polymer FTIR-ATR Spectra
𝑛CH3CH = CH2
catalyst
− CH2CH(CH3) 𝑛 −
Recycling statistics
The Curious Case of
Polystyrene
Conclusions
1970s: beginnings of
widespread plastic
packaging and containers
2009: plastic packaging
accounted for 30% of
packaging sales
80010001200140016001800200024002800320036004000
1/cm
45
52.5
60
67.5
75
82.5
90
97.5
105
%T
2962.66
1714.72
1452.40
1408.04
1238.30
1116.78
1091.71
1041.56
1016.49
974.05
873.75
842.89
723.31
STD_ PETE_clear
80010001200140016001800200024002800320036004000
1/cm
45
52.5
60
67.5
75
82.5
90
97.5
105
%T
2914.44
2846.93
1471.69
1462.04
719.45
STD_ HDPE_white
80010001200140016001800200024002800320036004000
1/cm
65
70
75
80
85
90
95
100
105
%T
2949.16
2916.37
2868.15
2837.29
1454.33
1436.97
1375.25
1357.89
1166.93
972.12
STD_ PP_clear
80010001200140016001800200024002800320036004000
1/cm
80
82.5
85
87.5
90
92.5
95
97.5
100
102.5
%T
3059.10
3024.38
2920.23
1600.92
1492.90
1452.40
754.17
696.30
STD_ PS_clear
𝑛CH2 = CHCl
catalyst
− CH2CH(Cl) 𝑛 −
Can IR be used to rapidly identify
unlabeled plastics?
Instrumentation:
Shimadzu Affinity-1
Fourier Transform
Infrared (FTIR) Spectrophotometer
with Attenuated Total Reflectance
Accessory
(ATR)
EPA, 2012:
• Almost 14 million tons as containers and
packaging
• ~11 million tons as durable goods
• Almost 7 million tons as nondurable goods
• 9% of plastic waste (2.8 million tons)
generated was recovered for recycling
• 28% of HDPE bottles and 31% of PET
bottles & jars were recycled
• ~12% of bags, sacks, & wraps were recycled
251 Million
Tons
ethene
𝑛CH2 = CH2
catalyst
−[CH2CH2] 𝑛 −
polyethylene
propene polypropylene
𝑛CH2 = CH(Ø)
catalyst
− CH2CH(Ø) 𝑛 −
styrene polystyrene
• Water, soft drink,
juice bottles
• Balloons
• Soap and lotion
bottles
HDPE:
• Garbage bags
• Cleaning product
containers
• Industrial products
• Personal care product
containers
LDPE:
• Shopping bags
• Dry cleaning bags
• Plastic food wrap
• Plumbing pipes
• Park benches
• Medical tubing
• Construction products
• Non-food bottles
• Window fittings
• Fencing
• Disposable cutlery,
cups, bowls
• Packing peanuts
• Styrofoam containers
• Take-out food
containers
• Automobile parts
• Laboratory Equipment
• “Microwave safe”
food containers
• Carpeting and
upholstery
• Toys
FTIR Spectrum of Polystyrene without the
ATR accessory
FTIR Spectrum
of Polystyrene with the ATR accessory
(Note the large difference!)
C=O
Alkyl
C-H
C-Cl
Alkyl
C-H
800100012001400160018002000240028003200
1/cm
88
90
92
94
96
98
100
102
%T
3059.10
3024.38
2920.23
1600.92
1492.90
1452.40
754.17
STD_ PS_clear
96
98
100
%T
1944.25
1869.02
1799.59
1734.01
00.92
1583.56
1541.12
1371.39
1350.17
1327.03
1278.81
This work was funded by the Independent
College Fund of New Jersey (ICFNJ). We
would like to thank Bloomfield College and
Jim Flood (Shimadzu) for technical support.
Mono-substituted
aromatic
• IR can be used to rapidly identify unlabeled
plastics
• HDPE and LDPE spectra are identical
(difference is only their density)
• Unlabeled plastics greatly outnumber labeled
plastics
• Most plastics are not recycled
• All plastics should be labeled AND recycled
• New labeling categories should be established
for resins grouped in the “other” category
Final Statement: Plastic consumption must be
reduced and its recycling must be increased.
CH2 bend
polyvinyl chloridevinyl chloride
polyethylene terephthalate