Innovation in size based polymer separations

©2014 Waters Corporation 1

“Innovation in Size Based Separations"


Current Status on Method Development for GPC

GPC needs method development – However, there are challenges that prevent routine method

development o Time constraints due to lengthy analysis times o Columns/ systems often dedicated to one solvent o Screening of conditions often not a viable option

– And now there are new challenges that make method development even more critical o Complex polymer chemistry o Many more process situations o Faster reactions – in process monitoring a challenge


Advanced Polymer Chromatography A Definition

Application technique for the size based separation of polymers in

solution using columns packed with sub-3µm, rigid, high-pore-

volume, hybrid particles combined with a robust, fully optimized low

dispersion ACQUITY system


The ACQUITY® Advanced Polymer Chromatography™ (APC™) System

Precise solvent

management

Low system dispersion

Compatibility with

challenging solvents

Rigid, solvent-resilient columns

Versatile column

management

Stable refractive

index detection

Flexible and robust data processing

Wide range of APC

standards


Benefits of APC Approach to the SEC Experiment

Speed of Analysis

Routine bracketed

calibration

Method conditions screening capability

Flexibility

Innovative SEC column choices

Fast system equilibration

Automated solvent

exchange

Resolution

Separation of highly complex polymer blends

Accurate reliable

data


A Systematic Approach to Developing APC Methods

Speed of Analysis: Increased Data Points Method Development Factors

Flexibility: Column Selection Automated Solvent Change

Maximize Resolution: Data Processing and Reporting







High Resolution SEC Characterization

µ

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

Minutes2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00

Use multiple small pore columns in a bank to improve low MW resolution

of the Liquid Epoxy Resin

6.00 min.


4 samples including replicate bracketed calibration in 90 min

4 samples including replicate bracketed calibration • 90 min. with APC • 1 Day with Traditional GPC

Sample Test Set with APC Sample Test Set with GPC


Cellulose Based Polymer – Target Molar Mass 300,000 - Polystyrene Equiv. 100,000



High Throughput Screening SEC

Dextran 410k Dextran 47k Dextran 165k Dextran 1.75m

µRIU

0

2

4

6

8

10

12

14

Minutes 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 0.36 0.38 0.40 0.42

GPC Calibration Plot

Log

DP

w

2.4

2.6

2.8

3.0

3.2

3.4

3.6

Use a single short column to

achieve very fast elution times for your polymer in

screening applications







Column Selection Criteria

Surface chemistry – Aqueous or organic soluble polymer

Particle size

– smaller particles for higher resolution – larger particles to avoid shear degradation of very high MW components

Pore size

– depends on molecular weight range of sample – avoid exclusion of sample – maximize pore volume in required separation region

Column Length

– compromise between resolution and analysis time


Surface Chemistry

Two surface chemistries available – Designed for use with aqueous soluble polymers – Temperature rated up to 45C – pH range of 1 – 9

– Designed for use with organic soluble polymers – Temperature rated up to 90C – pH range of 1 - 11

AQ

XT


BEH Particle Resistance to Swelling

ACQUITY APC Columns are based on our BEH particle technology – Rigid pore structure – Excellent mechanical

stability – Excellent solvent

compatibility

But I have to select columns that are packed in my

chromatographic solvent to avoid bed swelling

Columns are shipped dry. Just equilibrate

with 20 column volumes of your chromatographic

solvent


Efficiency: Impact of Particle Size on SEC Separations

Data courtesy of Miroslav Janco, The Dow Chemical Co.

Column: ACQUITY BEH C18 (130Å, ~0.7 mL/g), 4.6x150mm; Sample: Polystyrene (Mp=11.6K, Đ=1.03); Mobile phase: THF; Detection: UV


Selecting the Correct Pore Size µR

IU

0.00

15.00

30.00

Minutes0.00 1.50 3.00 4.50 6.00

Selecting a column bank with a pore size range to cover the

MW distribution of the polymer is critical for getting an accurate measurements

2 Columns in series 45A + 125A 3 Columns in series 45A + 125A + 450A


Selecting the Column Length

µRIU

0.00

4.00

8.00

12.00

Minutes0.00 3.00 6.00

Selecting a column bank with increasing length will improve the resolution of

the separation

3 Columns in Series 30mm 75mm 150mm


Solvent Selection Criteria

Solubility – Need a solvent that can entirely dissolve your polymer to get real

measurement

Viscosity – What is the impact on the separation conditions? – Can it be managed?

Additives – How to identify and eliminate surface interactions to get purely SEC

mode separations

System/Detection Considerations – The solvent is compatible with your polymer, but what about the

chromatographic system?


Solvent Selection and Refractive Index

Ascending order of Refractive Index

Solvent Refractive Index

Hexafloroisopropanol 1.275 Methanol 1.329 Water 1.33 Acetonitrile 1.344 Acetone 1.359 Ethanol 1.361 Ethyl Acetate 1.37 Hexane 1.373 Methyl ethyl Ketone 1.379 Isopropanol 1.38 Heptane 1.387 Isooctane 1.404 Tetrahydrofuran 1.408 Dichloromethane 1.424 Dimethylformamide 1.428 Dimethylacetamide 1.438 Chloroform 1.443 N-methylpyrrolidone 1.468 Dimethyl sulfoxide * 1.477 Toluene 1.496

Test Polymer


Polysilane RI Detector Response with Toluene, THF and Ethyl Acetate

Solvent :Toluene (negative detector signal)

Solvent: Toluene (negative signal – detector polarity switch)

Solvent :THF (positive detector signal)

Solvent :Ethyl Acetate (positive detector signal)


Fully compatible with the ACQUITY APC supported solvents – 6 solvent lines

Enables automated solvent

switching on the ACQUITY APC System – Solvent resilient ACQUITY APC

hybrid particles not susceptible to swelling with solvent switching

Optional Solvent Select Valve




Flexibility: Column Selection Automated Solvent Change5



Epoxy 1009

ACQUITY APC XT 45A,125A,450A in Series 30mm 75mm 150mm

Use a range of columns in a bank to characterize broad samples and their trace oligomeric species

1 x 450Å (20,000-400,000) 150mm length 1 x 125Å (1,000-30,000) 150mm length

1 X 45Å (200-5,000) 150mm length

µRIU

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Minutes0.0 1.0 2.0 3.0 4.0 5.0 6.0


Choose Appropriate Calibration Kit


µRIU

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Minutes0.0 1.0 2.0 3.0 4.0 5.0 6.0

µR

IU

0.00

4.00

8.00

12.00

16.00

Minutes2.80 3.50 4.20 4.90 5.60 6.30

V1 = 1,800,000 + 277,000 + 34,800 + 3,470 V2 = 1,210,000 + 130,000 + 17,600 + 474 V3 = 552,000 + 66,000 + 9,130 + 266

Log M

ol W

t

3.0

4.0

5.0

6.0

Elution Volume2.50 3.00 3.50 4.00 4.50 5.00

ACQUITY APC Calibration Standards: Polystyrene

9 min

High MW Standards MW: 266 - 1,800,000 Columns: 45A + 125A + 450A 150 mm each THF at 0.8 ml/min 10 ul RI Detector


Data Review


Calibration Using Narrow Standards Polynomial – All data points fitted with one function of the form; Linear (1st order): Log M = A + B(V) Quadratic (2nd order): Log M = A + B(V) + C(V2) Cubic (3rd order): Log M + A + B(V) + C(V2) + D(V3) Fifth Order: Log M + A + B(V) + C(V2) + D(V3) + E(V4) + F(V5) Cubic Spline Sets of points fitted with a series of Cubic equations Point to Point Points fitted with a series of linear equations

Extrapolation


Set Calibration Limits V0 and Vt

V0

Vt


Alternate Data Processing How to Process – Single Mode Limits


Multi Mode Processing


Characterization of a Broad Epoxy Sample


Summary

APC method development follows the same workflow as GPC. A number of factors must be considered when developing a

robust and appropriate test method including; – Goal of analysis – Polymer properties – Solvent selection – Detector response

Factors such as solvent selection and use of solvent additives can be easily screened and scaled on a single column set.

Selection of calibration standards can be made to match column pore size.

Calibration can be easily added to all test sets Use of analysis specific processing can improve data consistency

and direct data reporting


The ACQUITY® Advanced Polymer Chromatography™ (APC™) System Innovation in Size Based Separations

Precise solvent

management

Low system dispersion

Compatibility with

challenging solvents

Rigid, solvent-resilient columns

Versatile column

management

Stable refractive

index detection

Flexible and robust data processing

Wide range of APC

standards


Thank you for your attention.

Questions?

Science

Innovation in size based polymer separations