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Solving Commercial Polyurethane Challenges in the Modern Analytical Laboratory

2012 PMA 41st Annual Meeting

April 22 - 24

Huiling Ding, PhD and Sr. Scientist

William A. Wortman, Sr. Scientist

Albert Nitowski, Sr. Manager

Chemtura Corporation, 12 Spencer Street, Naugatuck, CT 06770-4525

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Content

•  Introduction

•  Separation Sciences

•  Thermal Techniques

•  Spectroscopy –  Infrared (IR)

–  Nuclear Magnetic Resonance (NMR)

•  Classical analysis for chlorine

•  Conclusions

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Introduction

•  Analytical Services

–  Equipment and Staff to help solve problems

•  Provide Technical support : –  R&D, new product development –  Factory Service –  Technical Service / Customer Service

•  Typical Samples: •  Unknowns •  Defect Analysis •  Failure mode analysis •  Deformulation

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Separation Science / Mass Spec

•  Gas Chromatography (GCMS) –  Volatiles (Odors) –  Low Mw Components after extraction from Polymer

•  HPLC (LCMS) –  Free isocyanate level in prepolymers –  Raw material evaluations

• 

•  Gel Permeation Chromatography (GPC) –  MW and MWD on polyols and prepolymers –  Viscosity / Light Scattering / UV / RI Detectors

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Thermal Techniques

•  DSC Differential Scanning Calorimeter

•  TGA Themogravimetric Analysis

Hyphenated techniques: •  TGA-IR

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14.29% (2.556mg)

12.62% (2.257mg)

Residue:72.97% (13.05mg)

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50

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80

90

100

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

Sample: PU PolymerSize: 17.8850 mgMethod: Air Ramp 30-900C 20dpmComment: PU

TGAFile: C:\TA\Data\TGA\paper.dat

Run Date: 23-Feb-12 14:02

Universal V2.5H TA Instruments

TGA

•  Volatility •  Thermal Stability •  Composition

•  Plasticizer •  Ash

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Why FTIR Spectroscopy?

•  Powerful –  Often only test needed to ID Pure materials

•  Fast (2 minutes)

•  System Costs are low

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FTIR Spectroscopy •  Bonds Absorb IR at various frequencies

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55

60

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80

85

90

95

100

%T

500 1000 1500 2000 2500 3000 3500 cm-1

O-H Stretch

Wavenumber (energy)

CH3 Bend

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FTIR Spectroscopy •  Power in Search Libraries

•  Diamond ATR cells –  Little or no Sample Preparation

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Diamond ATR Cell ( Relatively Indestructible )

Diamond

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Clamp Sample Against Diamond

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Polyu rethane Bel t

0

10

20

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50

60

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80

90

100

%Tr

ansm

ittan

ce

500 1000 1500 2000 2500 3000 3500 Wavenumb ers (cm-1)

IR Spectrum for Unknown Polyurethane Belt

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Polyu rethane Bel t

0

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40

60

80

100

%T

PEBAG/MDI/BD polyu reth ane

0

20

40

60

80

100

%T

500 1000 1500 2000 2500 3000 3500 Wavenumb ers (cm-1)

97.5% Library Match

PEBAG/ MDI/ BD

Unknown PU Belt

Library Match for Unknown Polyurethane Belt

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FTIR Library Demo

A 10 minute Polyol library was developed:

- PBAG - PEBAG - PEAG - PCL - PTMEG -  PPG

O

Polyesters - C-O -

Polyether -C-O-C-

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Prepolymer Evaluation PEAG/MDI urethane prepolymer

0.0

0.5

1.0

Abs

Match:84.15PEAG

0.0

0.5

1.0

Abs

Match:71.75PEBAG

0.0

0.5

Abs

Match:55.03PBAG

0.0

0.5

Abs

Match:28.29PCL

0.0

0.5

Abs

Match: 3.11PTMEG

-0.0

0.2

0.4

Abs

500 1000 1500 2000 2500 3000 3500

cm-1

PEAG/MDI Prepolymer

PEAG 84% match

PCL 28% match

PEBAG 72% match

PBAG 55% match

PTMEG 3% match

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Cured Polyurethane Evaluation Title: PPG/TDI/MOCA

0.0

0.5

1.0

Abs

Match:72.17PPG-2000

0.0

0.2

0.4

Abs

Match:19.14PTMEG

-0.0

0.2

0.4

Abs

Match:10.58PCL

0.0

0.5

Abs

Match: 9.85PEAG

0.0

0.5

1.0

Abs

Match: 9.12PEBAG

0.0

0.5

Abs

500 1000 1500 2000 2500 3000 3500

cm-1

PPG 72% match

PPG/TDI/MOCA

PTMEG 19% match

PCL 11% match

PEAG 10% match

PEBAG 9% match

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IR Libraries

•  Custom library easily developed: •  Run Raw materials •  Finished goods

•  IR Libraries Commercially available.

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Human Hair

Blue Streak on Polyurethane surface

IR – Microscopy Small Defect Analysis

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FTIR Microscopy

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ATR Microprobe

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20 Micron Aperture

Reference spectra collected here

Surface Mapping ATR Microprobe

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Con tro l_Polyu rethane Surface

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%T

Blue_Stre ak

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80

100

%T

1000 1500 2000 2500 3000 3500 Wavenumb ers (cm-1)

Control Area

(95 Match PTMEG / TDI / MOCA)

Blue Streak

(85% match Phenoxy resin)

IR Results For Blue Streak

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- Minor Components -  Mixtures of similar components PEAG or PEBAG? - Complex Systems / Curatives

Limitations of IR

NMR Spectroscopy (Nuclear Magnetic Resonance)

A powerful tool for identification and quantification of PU

polymer backbone, curative and additives

Driving forces: - More variety of PU products

Isocyanates, Polyols, Curatives, Additives - Industry Globalization Differences between regions

NMR Instrument

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-  NMR Spectroscopy Scientists

-Work closely with PU experts - Well trained in PU chemistry - Focus on customer needs

-  NMR Lab and Instrument Design

-Nitrogen line ready for sample prep - Auto-switchable probe for 1H, 13C, 31P, 19F, etc.

1D and 2D NMR - Acquisition -150 to 150oC.

- Heated auto-sampler holders

Important Factors For Successful NMR Application

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Heated NMR Auto-sampler Keep PU NMR sample at proper temperature before acquisition

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MDI Aromatic

Additive Additive MDI

1,4-BD

PBAG

PEAG

Adipate

NMR for PU Component Identification and Quantification

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Advantages of NMR Component NMR Capability

General deformulation ID and quantify the ratio of polyol / isocyanate / curative / additives

Polyol – ether One or mixture of polyol / Ratio

Polyol – ester Specific ester type; molar ratio of monomers in copolymers; tri-functionality; initiators; chemical copolymers vs physically blended

Aromatic Isocyanates MDI / TDI and their isomer ratio in PU; PPDI - ratio of free / prepolymer / oligomer Other isocyanates like TODI, NDI ….

Aliphatic Isocyanates H12MDI, HDI, IPDI. Etc. in cast PU; and in dispersions.

Curatives routinely or rarely used curative, or mixture to lower level; measure curative theory.

Plasticizer, other additives,

Identification and quantification without standards, to lower ppm level.

Cross-contamination impurities in lower PPM level and up.

Hydrolysis quantitatively compare the urea group level between the bad and good sample.

Urethane, urea and allophanate groups

relative ratio

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H2O or HDO In NMR solvent

F

I J

E G H B

D

A

NMR solvent DMSO-d6

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NMR Analysis of Molar Ratio of Glycols in Polyol Copolymers OO

O

O O O OO

OO

O

OO OHOOH

n m

A B C D F F D D F E G HH I J J I I J J I I J J I

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NMR Analysis of Cross Contamination in PU Product - 1

Example 1: Urethane Belt Contaminated by Hydraulic Oil

Rat Eaten Belt

Good Belt 1

Good Belt 2

OilOil

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NMR Analysis of Cross Contamination in PU Product - 2

Example 2: Carboxylic Acid in Degraded Ester/MDI material

Carboxylic Acid

Good Control

Degraded 1

Degraded 2

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NMR Analysis of Cross Contamination in PU Product - 3

Example 3: Polyester Curative Contaminated with TIPA and TMP – 1H NMR

TIPA Standard

GoodEster CurativeClear

Contaminated Ester CurativeYellow

TIPATIPA

TIPA Excess TMP

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NMR Analysis of Cross Contamination in PU Product - 4

Example 3: Polyester Curative Contaminated with TIPA and TMP – 13C NMR

TIPA Standard

Contaminated Ester CurativeYellow

TIPATIPA

TMP

NMR SolventDMSO-d6

NMR Analysis of Cross Contamination in PU Product - 5

Example 4: Cured Urethane Contains Extra Additives – 1H NMR

Good Lab Control S

Customer Cured PU Sample

Naugard 76

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NMR Analysis of Cross Contamination in PU Product - 6

Example 4: Cured Urethane Contains Extra Additives – 31P NMR

Triphenyl Phosphine Oxide

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NMR Analysis of PU Hydrolysis

Plant RetainPrepolymerSample

Customer PU PrepolymerSample

Relative higher level of Urea

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NMR Analysis of PU Curative Theory – 1

Example 1: Measurement of Duracure C3LF Curative Theory% in Duracast Material ( S700 / C3LF )

y = 0.0027x + 0.2628R2 = 0.9722

0.5100

0.5150

0.5200

0.5250

0.5300

0.5350

0.5400

0.5450

94 96 98 100 102 104 106

C3LF Curative Theory%

NMR

Sign

al

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NMR Analysis of PU Curative Theory - 2

Example 2: Measurement of 1, 4-BD Curative Theory% in MDI Polyurethanes

Ambient Temperature 500 MHz and 300 MHz 1H NMR Comparison of PTMG1000 / 1,4-BD / TMP

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NMR Analysis of PU Curative Theory - 3

Example 2: Measurement of 1, 4-BD Curative Theory% in MDI Polyurethanes (B635 / BD)

(500 MHz Acquisition temperature: 100oC)

y = 0.303x + 254.19R2 = 0.9991

280.00

281.00

282.00

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285.00

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287.00

288.00

88 93 98 103

1, 4 - BD Curative Theory%

NMR

Sign

al

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Classical Tests Schöniger Combustion / Titration

for Chlorine Containing (MOCA, MCDEA) Curatives

Schoniger Combustion, O2

Physical Transfer

Cl Absorption

Titration AgNO3

Weigh mg levels

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Classical Test – 2 Schöniger Combustion / Titration for MOCA Curative

Sample ID %Chloride Mean Std Dev %RSD

Cured 1 2.826 2.825 0.015 0.537

Cured 1 2.840

Cured 1 2.810

Cured 2 2.935 2.942 0.007 0.254

Cured 2 2.950

Cured 2 2.940

Cured 3 4.597 4.596 0.001 0.017

Cured 3 4.595

Cured 3 4.596

Cured 4 4.695 4.681 0.024 0.505

Cured 4 4.694

Cured 4 4.654

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Conclusions Summary of Analytical techniques in Polyurethane analysis

Analytical Techniques Main applications FTIR Diamond ATR Cell Qualitative PU backbone and inorganic filler analysis FTIR Microscope System Small area defect analysis and mapping NMR Spectroscopy Identification and quantification of PU polymer backbone, curative and

additives TGA Weight loss and ash test DSC PU heat transform test GPC Test polyol and Polyurethane prepolymer MW distribution Gas Chromatography Quantification of volatile PU components, raw material, curative and additives

LC Chromatography Quantification of PU components, raw material, curative and additives GCMS Identification of volatile PU components, raw material, and additives LCMS Identification of Polyurethane components, raw material, and additives Pyrolysis-GCMS Identification of non-soluble Polyurethane materials Classical Analysis Quantification of chlorinated curative and residue impurities UV/Vis Spectrometer Quantification and confirmation of Color body in Polyurethane

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Acknowledgments

Mrs. Diane Foell Mr. Bill Parente