Example shows that neither chromatography nor spectroscopy by themselves are adequate for characterization. Chromatography provides no molecular identification. Infrared spectrometric identification is of very limited utility in a multi-component sample.
3-Dimensional view of GPC-FTIR data set The use of a 3-dimensional view of a DiscovIR data set is often a good starting point for the data analysis. The individual spectra are displayed in the X-Y plane with the elution order (elution time, min) displayed along the Z axis of the plot. Inspection show that the sample (a hot melt adhesive) is a blend of polymeric-oligomeric components; each with distinct spectral bands and elution profiles.. All components show strong absorbance in the C-H stretch and bend frequencies. There are different relative intensities in the C-H stretch eluants, suggesting different composition. The two earliest eluants manifest carbonyl bands, and a close inspection of the data reveals slightly different peak frequencies of these carbonyls. The second eluant demonstrates various bands attributable to C-O absorbances. The third eluant appears to be a low molecular weight alkane hydrocarbon. When selected spectra from the three principal eluants are examined using a spectral data base, the materials are identified as EVA, a rosin ester, and a paraffin.
Figure. GPC-IR peak chromatogram and band chromatogram at 1724 cm -1 of hot melt adhesive sample
Figure. Database search of GPC-IR spectrum (red) at 10min. Elution time with a library standard IR spectrum (green) of EVA copolymer.
Figure. Spectra of the GPC doublet peak of hot melt adhesive sample
Figure. Spectral identification is supported by elution times of discrete standards: EVA copolymer, glycerol ester rosin and paraffin.
Point out starting monomers. Polyethylene backbone. Styrene provides 2 carbons to backbone, one with phenyl. Butadiene provides 4 carbons to backbone, 1 double bond. If monomers are mixed during synthesis, get random distribution. Blocks form by sequential addition of monomers. End blocks of polystyrene form crystal clumps, with the elastomeric carbon chains crosslinking the clumps. Specific IR bands for the PE backbone, cis double bonds, trans double bonds, and phenyl provide windows to the composition. Note ½ of backbone carbons are methylenes.
Figure. GPC-IR application summary to characterize poly (A-B) copolymers and to de-formulate polymer mixtures.
GPC-IR To Charaterize Polymer Mixtures--Akron Workshop
Advanced Polymer Characterization Akron Workshop -- 7/17/2012 GPC-IR to Characterize Copolymer Compositions andto Deformulate Complex Polymer Mixtures Ming Zhou, PhD Director of Applications Engineering Spectra Analysis Instruments, Inc. Marlborough, MA Contact: ZhouM@Spectra-Analysis.com 1 Tel. 508-281-6276
Hyphenated Technologies & Major Applications LC-MS LC-IRSeparation Liquid Chromatography Liquid ChromatographyDetection & Mass Infra Red Infra Red Spectroscopy Spectroscopy SpectroscopyData AnalysisApplications Small Molecules Copolymer Compositions Proteins Polymer Mixtures Additive Analysis LC = GPC / SEC or HPLC
GPC-IR Hyphenated System: Principle and Information OutputGPC for the Separation ofthe Polymers by MW or SizeInfrared Spectroscopy forCompositional Information
Principle of a GPC-IR Hyphenated SystemGPC DiscovIR-LC •Chromatography eluant is nebulized and stripped of mobile phase in the Hyphen •Analytes deposited as a track on a rotating ZeSn disk. •Track passes through IR energy beam of built-in interferometer. •A time-ordered set of IR spectra are captured as a data file set.
LC-IR Hyphenated SystemSystem Control Deposition Hyphen HPLCData Processing Microscopic FTIR Desolvation or GPC
Hyphen: A Proprietary Desolvation Technology N2 Addition Cyclone Thermal Cyclone EvaporatorFrom LC Evaporator Nebulization Air Cooled Condenser Patent pending: Chilled PCT/US2007/ Condenser 025207 Particle Stream to DiscovIR Waste Solvent
Desolvation Stage #1: The Thermal Nebulization•The thin-wall stainless steel capillary tube nebulizer is regulated toevaporate approximately half the solvent (electric heating).•Solvent expansion upon conversion to vapor increases the nebulizerback pressure and create a high-speed jet of micrometer-sized liquiddroplets that contain all the solute.•Gradients are acceptable as it is a self regulating system (gradientchanges monitored by changes in electrical resistance).
Desolvation Stage #2:Inside the Cyclone Evaporator •Centrifugal force holds the droplets (solute) near the cyclone wall. Just before the droplet goes to dryness, its volume to surface ratio becomes small enough that it is dragged out of the cavity by the exiting solvent vapor. •Evaporative cooling protects the solute from both evaporation and degradation by limiting the maximum solute temperature to the solvent boiling point. The solvent boiling point is reduced by operating the cyclone in a vacuum.
At the Condensers Series of Condensers• After ejection from the cyclone, solvent vapor is removed by diffusion to, and condensation on, the cooled condenser walls.• Stokes drag from the nitrogen gas maintains the dried droplets in an aerosol suspension and limits their loss by diffusion to the condenser walls.• The condenser consists of an air cooled stage followed by a Peltier cooled stage.• The condensed solvent is collected in a waste bottle.
ZnSe Sample Disk Rotate at tunable speed 10-0.3 mm/min Unattended overnight runs/10h The yellow ZnSe disk is under vacuum without moisture or CO2 interference Disk Temp: - 50C ~ 100C Transmission IR analysis is done on the solid deposit. Re-usable after solvent cleaning Mid-IR transparent 12
What is Direct Deposition FTIR?Separated Dot Depositing on Disk Separated Dots from HPLC-IR Continuous Polymer Tracks (GPC-IR)
Features of DiscovIR-LC System Real-Time On-line Detection Microgram Sensitivity All GPC/SEC Solvents: e.g. THF, TCB, HFIP, Chloroform, DMF All HPLC Solvents, Gradients & Volatile Buffers e.g. Water, ACN, Methanol, THF, DMSO … High Quality Solid Phase Transmission IR Spectra Fully Automated Operation: No More Manual Fractionation Multi-Sample Processing: 10 Hr ZnSe Disk Time
GPC-IR: Direct Deposition & Data Processing ZnSe Disk 16
Characterizing Polymer Mixtures by GPC (Size) or IR (Composition) GPC: Chromatographic IR: Fingerprinting Separation of Components of Chemical Compositions• Provides size distribution (MWD). • Unambiguous identification only• No identification of practical for single species. polymers • Compounded IR spectra for mixtures. additives GPC only: 2 or 3 peaks ? IR only: Compounded spectra .04 C .2 .03 B? .15 .02 .1 .01 A .05 0 0 2 4 6 8 10 12 14 4000 3500 3000 2500 2000 1500 1000
Case #1: Deformulate an Adhesive Polymer Mixture: GPC-IR 3D View Competitive study of an adhesive:.05 for cost & margin comparison for technical evaluation.04.03 ec na b os ba.02 r 14 13 12.01 11 10 GPC Elution 9 0 Time, min 84000 3500 3000 2500 2000 1500 1000 2929 IR Wavenumber, cm-1 1724 C=O
GPC-IR Deformulation of the Adhesive Polymer Mixture B? C AMax (Band) Chromatogram at 2929 cm-1 B ASelected Band Chromatogram at 1724 cm-1
IR Database Search to Identify Peak A at 10 Min. as EVA Polymer-CH2 A2929 C=O 1724
GPC-IR to Identify Components C & B by Spectral SubtractionComponent C ParaffinComponent BGlycerol Rosin Ester
GPC Confirmation of the Identified Components with Known Stds A, B & C B C AABC
Case #2: Deformulate Lubricant Additives in SAE 15W-40 Motor Oil Identiﬁcation of additives like stabilizers, viscosity modifiers, etc. Stability: ageing & failure analysis Additive Y 12 11 Additive X 10 GPC Elution 9 Time 8 (Min. & MW) 3500 3000 2500 2000 1500 1000 Wavenumber, cm-1Low MW mineral oil (~85%) diverted after 12.2 min
Deformulation of Motor Oil Additive X at RT 9.2 MinutesIR database search: Styrene-Acrylate Copolymer
Deformulation of Motor Oil Additive Y at RT 12 MinutesIR database search: Polyisobutenyl Succinimide (PIBS)
Additive Deformulation in Motor Oil Lubricant by GPC-IR• De-formulated polymeric additives X & Y in motor oil lubricant• Additive X at retention time 9.2 minutes Narrow MW distribution ~ average 600K (GPC) Styrene-Acrylate copolymer (IR database search) Viscosity Index improver No Comonomer Compositional Drift Stable [700cm-1/1735cm-1] Band Ratio• Additive Y at retention time 10-12 minutes Broad MW range: 8-30K (GPC) Polyisobutenyl Succinimide (PIBS) (IR database search) Dispersant for metal particles Small Comonomer Compositional Drift [dimethyl (1367 cm-1) / imide (1700 cm-1)] Ratio Change < 10%• Polymer degradation study Analyze polymer breakdown or cross-linking by GPC Detect oxidized intermediates by IR Oil change schedule
Case #3: Deformulate a Flexible Conductive Ink by GPC-IRSilver ink paste filled with Ag particles (~80% Wt) • Designed to screen print flexible circuitry such as membrane switches • Extremely flexible after curing at 150°C for 30 minutes • Very conductive even under 20x folding / crease stress tests (ASTM F1683). 5 times better than the next competitor • Understand the unique formulation technology • Deformulate the complex polymer system
Deformulating the Conductive Ink GPC-IR Chromatogram Column: 2 x Jordigel DVB Mixed Bed Mobile Phase: THF at 1.0 ml/min Sample Conc.:~5 mg/ml in THF Injection Volume: 60 μl IR Detector Res.: 8 cm-1 ZnSe Disk Temp.: -10°C Cyclone Temp.: 130°C Condenser Temp.: 15°C Disk Speed: 12 mm/min
Stacked IR Spectra of Components A, B, C at their MWD ApexesNH
Commercial IR Database Search for Polymer A (Red): PolyesterIndex % Match Compound Name Library434 96.63 Amoco Resin PE-350 Polyester Coatings Technology (Thermo)450 95.96 Dynapol LH-812 Polyester Coatings Technology (Thermo)467 95.65 Vitel VPE-222F Polyester Coatings Technology (Thermo)443 95.06 Dynapol L-411 Coatings Technology (Thermo)466 94.45 Vitel PE-200 Coatings Technology (Thermo)
Commercial IR Database Search for Polymer B (Blue): Polyurethane NH OHIndex % Match Compound Name503 88.13 Spensol L-53 UROTUF L-53 Polyurethane949 87.51 Polyester Polyol 0305424 87.33 Polycaprolactone944 87.29 Polyester Polyol 0200212 86.86 UCAR Cyracure UVR-6351
Commercial IR Database Search for Component C (Red): Cross-linkerIndex % Match Compound Name834 92.47 Desmodur LS-2800, CAS# 93919-05-2, MW 766, Cross-linking Agent3249 65.30 Caffeine; 1,3,7-Trimethylxanthine9302 64.76 Monophenylbutazone615 62.15 Betulinic acid; 3-Hydroxylup-20(29)-en-28-oic acid860 62.05 Spenlite M-27
Reverse-Engineering the Conductive Ink by GPC-IR Deformulation • C: Desmodur LS-2800C • Ketoxime blocked HDI trimer • Latent cross-linking agent Curing (150oC / 30 min)B • De-blocked C cross-linking with Polymer B Chains • Interpenetrating with Polymer AA • Lock Ag fillers in place to form conductive circuitry • Super flexibility & elasticity • Superior end-use properties
Summary: GPC-IR to Deformulate Complex Polymer Mixtures• GPC-IR is well adapted for the de-formulation of complex polymer systems Separation of all the components of a mixture (polymer and small molecules) Detection of each component by IR (solid phase transmission) Identification by IR database search (commercial & proprietary databases)• Useful: For competitive analysis / IP protection To find specific raw material supplier For problem solving / trouble shooting / contamination analysis• Applicable to coatings, adhesives, inks, sealants, elastomers, plastics, rubbers, composites, biopolymers …
Copolymers: Poly(A-B), Poly(A-B-C),… Copolymers provide enhanced characteristics of individual comonomer constituents. In copolymers, important properties depend not only on MWD, but also on the chemical composition distribution. Compositional drift refers to small variations of the concentration of the comonomers across MWD. Copolymer product properties can be controlled/optimized by controlling composition drift characteristics.
GPC-IR to Characterize Compositional Variations of Copolymers Poly(A-B) IR Spectra Amolar mass BAbsorbance A/B composition ratio high MW low MW GPC Time polymer chains comonomer A comonomer B 39
Case #4: GPC-IR to CharacterizeComposition Drifts of SBR Copolymers Monomers: S & B Random SBS Block
GPC-IR Spectrum Snapshot of Styrene/Butadiene Copolymer Cove this The three bands filled in red arise from the styrene 698 comonomer (1605, 1495, and 698 cm-1) The green filled band (968 cm-1) is 968 generated by the butadiene comonomer. 1495 1605There is no significant overlap of any of these bands by the other comonomer species.
GPC-IR Analysis of SBR IR Spectra at Different Elution TimesCompositional analysis of SBR based on characteristic IR absorbancebands for styrene (1495 cm-1) and butadiene (968 cm-1). B 968 S 1495
Compositional Drifts across MWD for Styrene/Butadiene Copolymer B Bulk Average – 10% Styrene S/B Ratio S Compositional Changes with GPC Elution Time (MWD) for Comonomers Styrene(1495cm-1), Butadiene (968 cm-1) and their Ratios Styrene/Butadiene (1495cm-1 /968 cm-1)
Compositional Drifts across MWD for Styrene/Butadiene Copolymer B Bulk Average – 44% Styrene S/B Ratio S Compositional Changes with GPC Elution Time (MWD) for Comonomers Styrene(1495cm-1), Butadiene (968 cm-1) and their Ratios Styrene/Butadiene (1495cm-1 /968 cm-1)
Compositional Variations for Various SBS Copolymers (Bimodal)Dotted Curves:MWD Solid Curves: S/B Ratios
GPC-IR Spectrum of Copovidone Excipient - PVP/VAc CopolymerPeak 1680 cm-1 from VP comonomerPeak 1740 cm-1 from VAc comonomer
Copovidone PVP/VAc Compositional Drifts from Different Manf. Processes .6 Copovidone: sample A 50 sample B % acetate comonomer .5 sample C 45 .4 Molecular Weightmax. IR absorbance Distribution Comonomer Composition .3 Distribution 40 Bulk 40% VAc for All .2 35 .1 0 30 Molecular Weight 106 105 104 103 102 Copovidone A gave clear tablets while Copovidone C led to cloudy ones.
Case #5: GPC-IR to Characterize Compositions of MMA Copolymers Sample S MAA BA MMA DAAM Ratios A 5% 12.5% 10% 60% 12.5% A/E, S/E DAAM / E B 15% 10% 75% Acid/Ester C 25% 15% 10% 50% A/E, S/E D (50:50 Acid/Ester B/C Mix) 12.5% 15% 10% 62.5% S/EsterCo-Monomers: S MAA BA MMA DAAM CH3 C =O 1734 1700 1536 704 1734 1605 1366 2 right peak CH3 of doublet Peak Ratios: 704/1734 1700/1734 Total Ester 1734 Base 1536/1734, 1366/1734 E = Total (MMA+BA) 1536/1366 (Ratio Check
IR Spectrum Comparison (1800-1300cm-1) of All 4 Samples at 23.2 Min. (~MWD Center)normalized to carbonyl peak height: Ester (Total MMA + BA)1734 Sample A: Black Sample B: Blue Sample C: Violet Sample D: Green COOH 1700 DAAM Styrene 1366 1605 DAAM 1536
Styrene/Ester Ratios across MWD by IR Peak Ratios for MMA/BA/MAA Copolymer704/1734 Peak Height Ratio, No Styrene Sample B IR Spectrum at Red Marker IR Spectrum at Blue Marker
Styrene/Ester Ratios across MWD by IR Peak Ratios for MMA/BA/MAA/S Copolymer704/1734 Peak Height Ratio Sample CIR Spectrum at Red MarkerIR Spectrum at Blue Marker
Styrene/Ester Ratios across MWD by IR Peak Ratios for Sample D = 50%B+50%C704/1734 Peak Height Ratio Sample DIR Spectrum at Red MarkerIR Spectrum at Blue Marker
GPC-IR Chromatogram Comparison (B & C MWD Mismatch) of Samples B, C & D Sample B MMA/BA/MAA No Styrene Terpolymer Sample C MMA/BA/MAA/S Stable Styrene Level Tetrapolymer Sample D 50%B + 50%CStyrene Level Variation across MWD
Summary: Characterizing MMA Copolymers by GPC-IRSample S MAA BA MMA DAAM RESULTS (Acid) (Ester) (Ester) Ratios across MWD A 5% 12.5% 10% 60% 12.5% Stable S/E Ratio A/E Small Drift DAAM/E Small Drift B 15% 10% 75% S/Ester = 0 Acid/Ester Drifting DAAM/Ester =0 C 25% 15% 10% 50% Stable S/E Ratio A/E Small Drift DAAM/Ester =0D (50:50 S/Ester DriftingB/C Mix) 12.5% 15% 10% 62.5% Acid/Ester Drifting DAAM/Ester =0 54
Excipient Degradation from Hot Melt Extrusion (HME) Process Hot Melt Extrusion Process: To Make Solid Dispersions for Low Solubility Drugs to Improve Bioavailability Degradation Issues • Excipient & API Degradation at High Temp. (100-200C) • Discoloration / Residues • Degradant / API Interactions Process Variables • Temperature • Time (Screw Speed) • Torque • Screw / Die Designs 56
Case #6: GPC-IR to Analyze HPMCAS Degradation from HME Processing Polymer Change ?UnprocessedProcessed at 160C Degradant ?Processed at 220C
Degradant ID from HPMCAS (220C) in Hot Melt Extrusion ProcessIR Database Search Result: Succinic Acid
HPMCAS Polymer Degradation in Hot Melt Extrusion Process -C=O OHFunctional Group Ratio Changes from High Temp Process (Sample C)
Matrix Study: HPMCAS Excipient Stability & Degradation from HMESample # Extrusion Sample Sample Degradant Polymer Temp. Color in THF Formed ? Change? (~0.5%) Ref. Not White Clear None None Processed Powder Solution A 180 C Yellowish Clear Powder Solution B 200 C Yellowish Some ? ? Powder Residue C 220 C Brownish Some ? ? Powder Residue 60
Degradant Level Comparison of HPMCAS Samples after HME Band Chromatograms at 1670 cm-1 Sample C: Violet (220C) Sample B: Brown (200C) Sample A: Aqua (180C) Sample R: Blue (Ref.) Degradant at 14.6 Min.Normalized to Additive Level Additive at 14.1 Min.
Degradant Level Increases with Higher HME Processing Temp. ~190oCSamples: Ref. A B C
HPMCAS Matrix Study Summary: Degradation & Stability from HMESample # Extrusion Sample Sample Degradant Polymer Temp. Color in THF Formed Change (~0.5%) Ref. Not White Clear None None Processed Powder Solution A 180 C Yellowish Clear Little None Powder Solution Succinic Acid B 200 C Yellowish Some Succinic Powder Residue Acid C 220 C Brownish Some Succinic Higher Powder Residue Accid OH/C=O Ratio 63
GPC-IR Analysis of HPMCAS Degradation in HME Process Detected Degradants: Succinic Acid & Derivatives Detected Functionality Change: Ratio Hydroxyl Vs. Carbonyl Help Understand Polymer Degradation Mechanism Study Excipient / Drug API Interactions Define Safe Process Window: Quality by Design (QbD) Polymer Blends with Plasticizers and Additives HOOC-CH2-CH2-C=O CH3-C=O Figures: Schematic Structures of HPMC-AS Polymeric Excipient
Case #7: GPC-IR to Analyze PEA/MAA Degradation from HME ProcessSample # Extrusion Screw Sample Sample Degradant Polymer Temp. Speed Color in THF Formed Changed (~0.5%) ? ? S0 Not White Clear Processed Solution S1 130 C 250 rpm Off Clear White Solution S2 160 C 250 rpm Off Clear White Solution S3 190 C 250 rpm Brownish Some ? ? Residue Note: Samples S1-S3 contain 20% plasticizer TEC to assist extrusion process. 65
IR Spectra of PEA/MAA Samples at Polymer MWD Apex (ET ~9.4 Min.)S0 – Green Ref COOEtS1 – Violet 130C 1735S2 – Blue 160CS3 – Black 190C COOH 1705 NCE? 1805 cm-1 CO-OH 66
PEA/MAA Crosslinked to Anhydride from COOH at Higher HME Temp COOEt 1735 S0 – Green Ref S1 – Violet 130C S2 – Blue 160C COOH S3 – Black 190C 1705 NCE?1805 cm-1 67
PEA/MAA Matrix Study Summary: Degradation & Stability from HMESample # Extrusion Screw Sample Sample Degradant Polymer Temp. Speed Color in THF Formed Change (~0.5%) S0 Not White Clear None None Processed Solution S1 130 C 250 rpm Off Clear Trace White Solution Anhydrides S2 160 C 250 rpm Off Clear Anhydrides Acid/Ester White Solution Ratio Decreased S3 190 C 250 rpm Brownish Some Anhydrides Acid/Ester Residue Ratio Decreased 68
Common Polymeric Excipients for Hot Melt Extrusion Studied by GPC-IR ? HOOC-CH2-CH2-C=O HPMCAS ~ 190C COCH3 PEA/MAA ~ 160C HO O O N l O m n Copovidone > 200C O O O H - (OCH2CH2 )n - OH SoluPlus > 200C PEG HO Excipient Combinations with Plasticizers and Additives 69
IR Band Identifications of SoluPlus CopolymerHO Group VAc VCap Note PEG VCap O O C=O 1738 cm-1 1642 cm-1 Peak Ratios for N Compositional l O Drifts w/ MWD m n O Acetyl 1244 cm-1 Internal Ratio O Check vs. O Peak 1738 VAc CH3 1374 cm-1HO Peak 1642 cm-1 from VCap comonomer Methyl Acetyl 1374 1244 Peak 1738 cm-1 from VAc comonomer
SoluPlus Stability: VAc/VCap Ratios Drift Similarly across MWD after HME All VAc/VCap Ratios Within Lot-to-Lot VariationsR – Green Unprocessed ReferenceA – Black Processed at 120C @ 125rpmB – Blue Processed at 120C @ 250rpmC – Brown Processed at 180C @ 125rpmD – Violet Processed at 180C @ 250rpm 71
GPC-IR Matrix Study Summary: SoluPlus Stability in HME ProcessingSample # Temp. Screw Sample Solution Degradant Polymer (C) Speed Color in DMF Formed Changed ? (rpm) (~2%) ? R Not White Clear Not VAc/VCap (Ref.) Processed Powder Solution Detected Ratio Drift w/ MWD A 120 125 Off Clear Not Same White Solution Detected VAc/VCap Ratio Drift B 120 250 Off Clear Not Same White Solution Detected VAc/VCap Ratio Drift C 180 125 Yellowish Clear Not Same White Solution Detected VAc/VCap Ratio Drift D 180 250 Yellowish Clear Not Same White Solution Detected VAc/VCap 72 Ratio Drift
Summary: GPC-IR Applications in Polymer-Related Industries DiscovIR-LC is a Powerful Tool for Polymers, Additives & Materials Analysis Deformulate complex polymer mixtures: identify polymer components Characterize copolymer composition variations across MWD Characterize polymer changes: degradation or modification Useful: For competitive analysis / IP protection To find specific raw material supplier or qualify a second supplier For new copolymer R&D and process scale-up To characterize polymer degradation: ageing study, failure analysis For problem solving / trouble shooting as general analytical capability Applicable to Coatings, Adhesives, Inks, Sealants, Elastomers, Plastics, Rubbers, Composites, Biopolymers ……
Summary: GPC-IR to Deformulate Complex Polymer Systems IR Spectra X? Y? Z?IR ID A-B Copolymer C Polymer AdditiveIR Database Product Name Product # Brand NameSearch & Supplier & Supplier & Supplier
Summary: GPC-IR to Characterize Copolymer Compositions across MWD IR Spectra B A/B Ratios A A-B CComposition Supplier-to-Supplier Built-in Feature/Difference for IDDrifts & Lot-to-Lot Variations Copolymer R&D / Process ControlVariations & Incoming QC for Users
Summary: GPC-IR to Characterize Copolymer Degradation from Ageing / Processing A/B Ratios Degradation A-B C DegradantsDegradation Loss of Functional Group A (Reduced A/B Ratios) Polymer Breakdown ( Lower MW Degradants) Cross-linking ( Higher MW with New Functional Groups) Confirm No Degradation / Stability
DiscovIR-GPC to Characterize Polymer Stability in Lubricant Oils X0 ID: SEBSAgeing @ 170CG0: 0 hrG12: 12 hrG24: 24 hrG36: 36 hrG48: 48 hr X1 X3 Y0 X2 X4 Note: Base oil was diverted at 25 min.
Summary: GPC-IR Applications Profile Polymer Compositions = f (Sizes) Cross Linking Break Down IR Spectra B A A/B Ratio High MW Low MW GPC Elution Time Map out Copolymer Compositions (A/B Ratio) across MWD (Sizes) Study Lot-to-Lot or Supplier-to-Supplier Variations Characterize Polymer Degradation from Processing: Loss of functional group (Reduced A/B) 80 Cross-linking ( Higher MW) Break down ( Lower MW) & Detect low MW degradant De-Formulate Complex Polymer Mixtures
GPC-IR Applications: Model Cases• De-Formulate Complex Polymer Mixtures: PolyX + Poly(A-B) + Additives PolyX + PolyY + Poly(A-B-C) + Additives• Characterize Copolymer Compositions across MWD: Poly(A-B), Poly(A-B-C), Poly(A-B-C-D), …• Polymer Blend Ratio Analysis across MWD: PolyX + PolyY• Polymer Additive Analysis by HPLC-IR: Add. (SM or PolyX)• Analyze Polymer Changes: Degradation or Modification 81
Comparison of Max Band (Black) & Selected Band Chromatograms Band 1690 cm-1Max Band Band 1510 cm-1DefaultAt 1730 cm-1 A Band 730 cm-1 B C Elution Time (Min.)
Polymer & Small Molecule Analysis by GPC-IR for ABS Plastic w/ No Extraction StepGPC-IR Chromatogram (Blue) for ABS Sample and Ratio Plot of Nitrile/Styrene (2240 cm-1/1495 cm-1 in Green). Polymers Small Molecules Additives Impurities Degradants
Polymer Additive Analysis GPC-IR for ABS Plastic w/ No Extraction StepIR spectra at different elution times across the low MW peak of the SECanalysis of ABS. Spectra indicate presence of multiple components.
SEC-IR to Characterize Compositional Heterogeneity of Acrylate CopolymersRef.: Mark Rickard et al, FACSS2011, Dow Chemical Midland Corporate R&D Analytical Sciences
GPC-IR to Characterize Compositional Heterogeneity of Acrylate Copolymers Monomer Monomer Normalization Homopolymer FT-IR spectra Frequency Frequency 0.80 PBMA_reference1 0.75 PBMA PEA_reference 1168 1149 EA 1026 (cm-1) 1731 (cm-1) PMMA_reference 0.70 PBA_reference 0.65 PEA BMA 1072 (cm-1) 1731 (cm-1) 0.60 0.55 PMMA 0.50 PBA MMA 1149 (cm-1) 1731 (cm-1)Absorbance 0.45 1072 0.40 1026 0.35 BA 1168 (cm-1) 1731 (cm-1) 0.30 0.25 0.20 0.15 0.10 0.05 1350 1300 1250 1200 1150 1100 1050 1000 950 900 Wavenumbers (cm-1) Compositional profiles for each monomer were constructed via intensity ratios at selected IR bands normalized to the ester carbonyl intensity.