RAPID ASSESSMENT OF FLAME RETARDANTS IN ENGINEERING POLYMERS

Gary Stevens, Patrick BairdHenryk Herman and Will Mortimore

GnoSys UK Ltd, University of SurreyGuildford, Surrey GU2 7XH

SUMEEPnet-IeMRC Scientific and Technical ConferenceHenry Ford College, Loughborough, 19th March 2008

Introduction

Legislative drivers (REACH, WEEE & RoHS) require improved management of virgin and recycled materials and new approaches to efficient polymer and additive assessment

Need tools for rapid identification and qualification of plastic materials

Extend these to flame retardant identification and quantification

Require portability and ability to deal with plastics/additives in products

Development of portable near infrared/visible (NIR/VIS) wide wavelength spectroscopy (WWS) – for power and electronics sectors

Apply to the challenge of identification and quantification of brominated flame retardants in virgin and recycled polymers

Qualification of recycled plastics for enhanced application and economic value

Application 1

Application 2

Application ...

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Qua

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Polymer material pj

Degree ofQualification gj

Mellor and Stevens (2003)

WWS and Multivariate Statistical AnalysisWWS and Multivariate Statistical Analysis

•• Visual spectral range (electronic transitions): information Visual spectral range (electronic transitions): information relating to chemistry, colour, scattering and texturerelating to chemistry, colour, scattering and texture

•• NearNear--Infrared (NIR) spectral range (overtones and Infrared (NIR) spectral range (overtones and combinations of molecular vibrations) : information relating to combinations of molecular vibrations) : information relating to specific functional groups and their environmentspecific functional groups and their environment

•• MVSA: MVSA: ““UnscramblesUnscrambles”” spectral information (all of which is spectral information (all of which is used); regression of spectral data against known materials used); regression of spectral data against known materials characteristics picks out the information relating to the characteristics picks out the information relating to the ““targettarget”” parameters only parameters only -- concentration, properties, processibility, concentration, properties, processibility, performance.performance.

Measurement Approach Measurement Approach -- TRANSPECTRANSPECTMTM

spectrometer

Portable VIS-NIR System and General Probe

Universal Probe for Textured Materials

Spectrometer Unit

Probe/Computer/Spectrometer Interface

Conduit Cable for Optical Fibres and Power/Communication Lines

Diffuse Reflectance Probewith Remote Control

Characteristic WWS Spectra of Various Engineering Polymers

CRTs

HP dj 950

HP lj 1200

flat screens

PCs

keyboards

floppy disks

CRTs

HP dj 950

HP lj 1200

flat screens

PCs

keyboards

floppy disks

PCA, Plastic Enclosure Materials: PC2 v PC3PCA, Plastic Enclosure Materials: PC2 v PC3

Brominated Flame Retardants – ICL IP

Formulated with Sb2 O3 into engineering thermoplastics ABS, PC/ABS and HIPS

FR-1210 Decabromodiphenyl ether or DecaBDE

S-8010 Decabromodiphenyl ethane (commercial grade)

FR-1524 Tetrabromobisphenol A or TBBPA

FR-720 Tetrabromobisphenol A-bis(2,3 dibromopropyl)ether or TBBPA-bdpe

BC-58 TBBPA carbonated oligomer (commercial grade)

F-2016 Brominated epoxy, medium molecular weight

F-3014 Tribromophenol end capped brominated epoxy, low molecular weight

F-3020 Tribromophenol end capped brominated epoxy, medium molecular

F-3100 Tribromophenol end capped brominated epoxy, high molecular weight

FR-245 Tris(tribromophenyl)triazine or TTBPT

PC Clustering of Various Polymer Matrices with FRs

Cluster Plot for Various ABS, HIPS and PC/ABS with 0 to 10 wt% bromine content of various FRs.

Clustering of Various Br-FRs in ABS

Cluster Plot for ABS with 0 to 10 wt% of various Br-FRs with Sb2 O3 (AO).

TBBPA

Br-end capped epoxy

Br-epoxy

Analysis of FR-1524: Tetrabromobisphenol A (TBBA)

Characteristic VIS-NIR Spectra showing ABS with and without FR-1524

Analysis of FR-1524 - Tetrabromobisphenol A (TBBA)

Predicted FR-1524 concentration in ABS compared to known gravimetric concentration

Analysis of FR-2016 - Brominated Epoxy, med-MW

Characteristic VIS-NIR Spectra showing ABS with and without FR-2016

Analysis of FR-2016 - Brominated Epoxy, med-MW

Predicted FR-2016 concentration in ABS compared to known gravimetric concentration.

WWS Summary

• WWS - MVSA is good at rapid polymer identification, colour index measurement and qualification (other work)

• It is able to identify and quantify the lower brominated FRs down to typically 0.1% b.w.

• It is not able to clearly identify and unambiguously quantify the Deca-DBEs (ether and ethane), Tris(tribromophenyl)triazine and Sb2 O3

Consider Raman spectroscopy with MVSA

Raman Spectra of DecaBDE and Polymer Matrices 

-150

-100

-50

0

3500 3000 2500 2000 1500 1000 500

Energy / Raman Shift (cm-1)

FR-1210

HiPS

PC

ABS

Raman Spectra of Highly Brominated FRs

Comparison of DecaBDE (1210),TTBT (245), TBBPA-bdpe (720) and ABS

 

0

10

20

30

40

50

60

800 700 600 500 400 300 200

Energy / Raman Shift (cm-1)

FR-1210

FR-245

FR-720

ABS

Raman Spectra of DecaBDE + ATO in HiPS

0

1

2

3

4

5

6

7

700 600 500 400 300 200 Energy / Raman Shift (cm-1)

HiPSHiPS, 2 .4% DecaBDEHiPS 12.0% DecaBDEDecaBDEAO112 (x)

AO112

Raman Spectra of DecaBDE + ATO in HiPS

0

1

2

3

4

5

6

7

340 320 300 280 260 240 220 200 Energy / Raman Shift (cm-1)

HiPSHiPS, 2 .4% DecaBDEHiPS 12.0% DecaBDEDecaBDEAO112 (x)

Quantification of DecaBDE + ATO in HiPS

0.46% accuracy

Quantification of Sb2 O3 in HiPS

0.1% accuracy

Raman Spectra of DecaBDE + ATO in ABS

0

50

100

150

200

250

300

1100 1000 900 800 700 600 500 400 300 200

Energy / Raman Shift (cm-1)

ABS, no FR, no AOABS, 2.4 % Deca BDE

ABS, 12.0 % Deca BDEDeca BDE

AO112 (crosses)

Raman Spectra of DecaBDE + ATO in ABS

0

50

100

150

200

250

300

700 600 500 400 300 200

Energy / Raman Shift (cm-1)

ABS, no FR, no AOABS, 2.4 % Deca BDE

ABS, 12.0 % Deca BDEDeca BDE

AO112 (crosses)

AO112

Quantification of DecaBDE in ABS

0.17 % accuracy

Quantification of Sb2 O3 in ABS

0.09 % accuracy

Conclusions• WWS-MVSA is capable of rapidly identifying and quantifying

engineering thermoplastics and many Br-FR systems

• The WWS method is less sensitive to the highly bromine substituted FR compounds but has colour index information

• WWS cannot identify and quantify DecaBDEs (ether and ethane) and Tris(tribromophenyl)triazine

• Raman measurements show clear discrimination and sensitivity to all Br-FRs including DecaBDEs and ATO

• Raman-MVSA can predict FR concentration to an accuracy 0.1% b.w. or better

• We plan to develop new portable Raman instrumentation for the rapid identification and measurement of brominated FRs and others

• Will support formulators, recyclers, supply chain and regulators & agencies in REACH, WEEE, RoHs and possibly VECAP extension.