Full Scan GPC-IR Characterization of

Polyolefin Copolymers and Blends

Ming Zhou, William Carson,

Sidney Bourne & Tom Kearney

Spectra Analysis Instruments, Inc.

March 1, 2011

Contact: ZhouM@Spectra-Analysis.com

Tel. 508-281-62761

2011 Int’l Polyolefin Conference

OUTLINE

GPC-IR Hyphenated Technology: Instrumentation

GPC-IR Applications: Case Studies

• Copolymer Compositional Analysis: SBR, SEBS

• Polyolefin SCB Analysis by High Temp GPC-IR: EP, EB, EH & EO

• Polyolefin Blend De-Formulation: PP+EP+EB

Summary

2

Hyphenated Technologies &

Major Applications

Liquid Chromatography

Mass

SpectroscopyInfra Red

Spectroscopy

Separation

Applications Small Molecules, Proteins Copolymers & Mixtures

Detection &

Data Analysis

LC-MS LC-IR

Pharma API’s Polymeric Excipients

GPC-IR Hyphenated SystemGPC–Desolvation–IR Analyzer

Dell Desktop ComputerThermo-GRAMS /32 Software Package

•Library Search & Creation

•Ratio Chromatograms

•CFR 21-Part 11 Compliant

4

LC-IR Hyphenated System

GPC or

HPLC

How is the Solvent Removed?

Cyclone

EvaporatorThermal

Nebulization

From LC

Nitrogen Addition

Chilled

Condenser

Waste Solvent

Particle Stream to Deposition Disk

Air Cooled

Condenser

Cyclone

Evaporator

Patent pending:

PCT/US2007/025207

Direct Deposition FTIR &

Data Processing (GPC-IR)

ZnSe Disk

7

ZnSe Sample Disk

Rotate at std speed

3mm/min or slow speed

0.3mm/min

Auto sampler compatible

Unattended overnight runs

The yellow ZnSe disk is

under vacuum without

moisture or CO2 interference

Re-usable after solvent

cleaning

Transmission IR analysis is

done on the solid deposit.

8

What is Direct Deposition FTIR?

Continuous Polymer Tracks (GPC-IR)Separated Dots from HPLC-IRSeparated Dot Depositing on Disk

Features of DiscovIR-LC System

Real-Time On-line Detection

Microgram Sensitivity

Compatible with all HPLC Solvents and Gradients

• e.g. Water, ACN, Methanol, THF, Chloroform

Compatible with all GPC/SEC Solvents: e.g. TCB, DMF, HFIP

High Quality Solid Phase Transmission IR Spectra

Fully Automated Operation: No More Manual Fractionation

Multi-Sample Processing: 10 Hr ZnSe Disk Time

11

Compositional Drift Analysis of

Copolymer Poly(A-B) by GPC-IR

Ratio 10/8 12/12 2/4 Total 24/24

A% 56% 50% 33% 50%

High MW Low MW Molar Mass

Ab

so

rpti

on

A/B RatioA

B

Compositional Drift Analysis of

Poly(A-B) by Various Techniques

Ratio 10/8 12/12 2/4 Total 24/24

A% 56% 50% 33% 50%

High MW Low MW Molar Mass

Ab

so

rpti

on

GPC-IR

A/B Ratio

Bulk 50% (NMR)Regular IR

(MS)

GPC-IR Spectrum Snapshot of

Styrene/Butadiene Copolymer

The green filled band (968 cm-1) is

generated by the butadiene

comonomer.

There is no significant overlap of any of these bands by the other

comonomer species.

Cove thisThe three bands filled in red arise from the styrene

comonomer (1605, 1495, and 698 cm-1)

Compositional Drifts across MWD

for Styrene/Butadiene Copolymer

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)

Bulk Average – 10% Styrene

GPC-IR Spectrum Snapshot & Band

ID for SEBS Block Copolymers

-(CH2-CH)k-(CH2-CH2)m-(CH2-CH)n-(CH2-CH)l –

S E B S

CH2-CH3

S1

1493

S2

700

BB2

2924

BB1

1465

B

1379

BB = Backbone

SEBS Ratio Overlay w/ MWD

BB1/BB2 (Flat), B/BB1, S1/BB1, S2/BB1

High Temperature GPC-IR Test

Conditions for SCB Analysis

18

GPC: Waters 150C

Solvent : TCB

Temperature: 145C

Column: J ordi DVB Mix Bed 25cm x 1cm Size 5 mm

Flow Rate: 1 ml/min

Sample: 2.5 mg / ml with 200ppm Irganox 1010

Injection Volume: 100 ml

Transfer Line Temperature: 150C

DiscovIR-LC Conditions:

• Cyclone Temperature: 375C

• Chamber Vacuum: 2 Torr

• Disk Speed: 3 mm/min (Standard)

0.3 mm/min (Slower for thicker deposition)

(Better Sensitivity in IR Fingerprint Region)

High Temp GPC-IR Spectra for

Polyolefin Branching Analysis

Ethylene-Propylene Copolymer (40% PP), Solvent TCB @ 150C

High Temp GPC-IR Removes

TCB Solvent for SCB Analysis

DiscovIR-LC Removes TCB Completely and Gives Clean IR Spectrum (Blue).

Polyethylene Sample with & without TCB Solvent

Polyolefin Branching Analysis by

GPC-IR for EP Copolymer

Copolymer Compositional Drift ~ CH3 Branching ~ Peak Ratio A1378/A1468

GPC-IR Chromatogram of EP Copolymer Overlaid with Peak Ratio Abs1378/Abs1468

(Molecular Weight Distribution)

-(CH2-CH2)m-(CH2-CH)n-

CH3

HT GPC-IR Spectra of

Ethylene-Hexene Copolymers

Butyl Branching ~ Peak Ratio A1378/A1368-(CH-CH2)m-(CH2-CH2)n-

CH2CH2CH2-CH3

Butyl Branching Analysis of

Ethylene-Hexene Copolymers

Butyl Branching Numbers per 1000 Backbone Carbons with Elution Time (MWD)

(Molecular Weight Distribution)

N butyls/1000 c

10

12

14

16

18

20

22

24

26

8 9 10 11 12 13 14 15

elution time, min

N b

uty

ls/1

000 c

-(CH-CH2)m-(CH2-CH2)n-

CH2CH2CH2-CH3

Area Ratio = Area (2940-3100cm-1) / Area (2940-2800cm-1)

Polyolefin Short Chain Branching

Analysis by Chemometrics

GPC-IR Chromatograms Overlaid with Area Ratios of EP Copolymer

(Molecular Weight Distribution)

Area Ratio = Area (Peak 1375 cm-1) / Area (Peak 1465 cm-1)

Branching Levels (Area Ratios) with a GPC-IR Chromatogram

(Molecular Weight Distribution)

GPC-IR Branching Analysis of

Dow ENGAGE® Polyolefins

-(CH-CH2)m-(CH2-CH2)n-

CH2CH2CH2CH2CH2-CH3Ethylene-Octene: 8100, 8200

8401, 8540

Area Ratio = Area (2940-3100cm-1) / Area (2940-2800cm-1)

GPC-IR Branching Analysis of

Ethylene-Octene Copolymers

GPC-IR Chromatograms Overlaid with Area Ratios

(Molecular Weight Distribution)

Higher Sensitivity than Peak Ratio Method at Low Branching Levels

EP(~40%)

HDPE

EO (~3%)

EO(~2%)

EO(~1%)

HT GPC-IR to Identify Branch

Types in IR Fingerprint Region

Branch Type Comonomer

Type

IR Bending

Frequency

Branch Identifier

(cm-1)

Methyl Propylene 1377 cm-1 1151

Ethyl Butene 1379 cm-1 772

n-Butyl Hexene 1378 cm-1 894

iso-Butyl 1383, 1385 cm-1 1169

n-Hexyl Octene 1380 cm-1 890

At slower disk speed (0.3mm/min), GPC-IR deposits much thicker polymer films to

give much higher sensitivity in IR Fingerprint Region with unique bands for branch

type identification.

Sample 3 (Blue) is a mixture of polypropylene homopoylmer,

ethylene/propylene copolymer & ethylene/butene copolymer

Polyolefin Mixture Analysis

(De-Formulation) by GPC-IR

ethylene/propylene copolymer

polypropylene

Sample 3 is a mixture of polypropylene homopoylmer,

ethylene/propylene copolymer & ethylene/butene copolymer

Polyolefin Mixture Analysis

(De-Formulation) by GPC-IR

GPC-IR Chromatogram with Specific Wavenumbers

PP & EP (1155)

EP & EB (720)

Isotactic PP (974)

EB (772)

Summary

30

High Temp GPC-IR Takes Snapshot IR Pictures of Polyolefin Copolymers for

Compositional Drifts and Short Chain Branching Analysis with MWD

Short Chain Branching Levels can be Analyzed either by Peak Height Ratios

or Peak Area Ratios for Ethylene Copolymers with Propylene, Butene, Hexene

and Octene.

GPC-IR can Analyze Short Chain Branching Levels of Ethylene Copolymers

from Multiple IR Ranges: 2800-3000, 1500-1300 and 1300-700 cm-1.

At Slow Deposition Speed (0.3mm/min), GPC-IR Provides Rich IR Data in

Fingerprint Region (1500-700 cm-1), Capable to De-Formulate Complex

Polyolefin Mixtures such as PP, EP & EB Blend.

Full Scan GPC-IR is a Powerful Tool to Characterize Polyolefin Copolymers

and Mixtures.

LC-IR Applications

GPC-IR is a Powerful Tool to Characterize Copolymers & Polymer Mixtures

Polyolefin Branching Analysis by High Temp GPC-IR

Analyze Copolymer Compositional/Structural Variations across MWD

Characterize Copolymer Modification and Degradation (Failure Analysis)

De-Formulate Polymer Mixtures and Additives

Analyze Polymer Blend Ratio across MWD

Process Control & Optimization

Plastics, Rubbers, Films, Fibers, Foams, Composites & Biopolymers

Reactive Polymer Analysis for Coating, Adhesive, Sealant & Elastomer

Isomer Analysis for Chemicals, Forensics & Pharmaceuticals

General Analytical Capability: Trouble Shooting31

Polymer Blend Ratio Analysis by

GPC-IR for EVA/PBMA Mixture

IR spectral bands of EVA & PBMA are closely overlapped.

The 1152 and 2852 cm-1 bands selected for minimal convolution.

Polymer Blend EVA/PBMA Ratios with

MWD from Spectral Peak Ratios

(Molecular Weight Distribution)

Calibration Curve: Y = 1.6162 X-0.2149 by Flow Injection Method w/o LC Separation

Y is Mass Ratio, X is Peak Ratio Abs(2852)/Abs(1152)

y = 1.6162x - 0.2149

0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.5 1 1.5 2 2.5

absEVA(2852)/absPBMA(1152)

mE

VA

/mP

BM

A