Functional Polymers Challenging ChromatographyChromatography

Ryan Mondschein, Alison Schultz, Justin M. Si ine Ch istophe B Williams and Timoth ESirrine, Christopher B. Williams, and Timothy E.

Long

Virginia TechDepartment of

ChemistryChemistryMacromolecules and Interfaces Institute

Blacksburg, VA 24061 USA

MII DREAMS LaboratoryMII DREAMS Laboratory1 mm

Where is Virginia Tech? Macromolecules and Interfaces InstituteMacromolecules and Interfaces Institute

Washington D.C.g

Blacksburg,g,Home of Virginia Tech

Macromolecules and Interfaces Institute From Molecules to ManufacturingFrom Molecules to Manufacturing

Founded 1975, currently 120 graduate students, 30 faculty, MACR graduate degreeInternational ranking, top-national ranking of polymer programs

Additive manufacturing: A synergy of novel geometry with materials designgeometry with materials design

vsvs.

http://www.compassdude.com/i/topographic‐map.jpg

4

http://upload.wikimedia.org/wikipedia/commons/6/68/Fotothek_df_n‐20_0000140_Zerspannungsfacharbeiter.jpg

Additive manufacturing: layer-by-layer (LbL) creation of physical 3D objects(LbL) creation of physical 3D objects

3D Printer3D CAD .STL Slicing 3DLayer Slices 3D Printer3D CAD Model

SFile

S c gSoftware

3D Object

Layer Slices and

Tool Path

3D printing advantageously allows:STL

3D printing advantageously allows:Customization of almost any objectHighly detailed objects with intricate geometriesDigital design and distribution of parts

(STereoLithography) is a file format native to the stereolithographyCAD ft t d Digital design and distribution of parts

Improved sustainabilityCAD software created

by 3D Systems.

Challenge, Opportunity, and InvitationAdditive manufacturing needs:

– Larger catalog of working materialsSt t P t P d t di– Structure-Property-Process understanding

Polymer chemistry opportunities:T il i h l / i it f AM– Tailoring rheology/viscosity for AM platforms with new macromolecular architectures

– Understanding intermolecular interactions at interfaces, surfaces, and interfacial phenomena

http://wohlersassociates.com/roadmap2009.html

phenomena– Physical properties of layered architectures– New orthogonal synthetic methods and

6

New orthogonal synthetic methods and photo-reactive monomers/oligomers

What are the advantages of phosphonium-based ILs and phosphonium ionomers?based ILs and phosphonium ionomers?

Ammonium PhosphoniumC tiCation Cation Nitrogen exhibits a partial negative charge

Phosphorus exhibits a partial positive charge

Does the cation structure influence macromolecular properties such as thermal stability and conductivity?

Does the cation structure impact coacervate formation with negatively p g ycharged macromolecules?

8

Aqueous SEC determined absolute molecular weights for all polyelectrolytesmolecular weights for all polyelectrolytes

M MPolymer dn/dc

(mL/g)

Mn(kg/mol)

Mw(kg/mol)

PDI

PTMA 0 203 225 311 1 38PTMA 0.203 225 311 1.38PTEA 0.179 251 395 1.57PTPA 0.197 167 238 1.43 0.80

1.00

nsit

y

PTBA 0.165 250 391 1.56PTMP 0.185 235 292 1.25PTEP 0 190 270 388 1 44

0.40

0.60

tive

Int

en

PTEAPTBAPTEPPTEP 0.190 270 388 1.44

PTPP 0.189 342 553 1.62PTBP 0.195 314 499 1.59 0.00

0.20

15 25

Rel

at PTEPPTBP

Aqueous SEC: 54/23/23 H2O/MeOH/AcOH 0.1M NaAcetate, MALLS 9

15 25Time (min)

RAFT polymerization created the desired phosphonium diblock copolymersphosphonium diblock copolymers

RAFT polymerizationRAFT polymerization successfully controlled the molecular weight

10

Anion exchange of phosphonium 4-vinylbenzyl trioctyl phosphonium chloride achieves a photo-curable ILcurable IL

Low Tm for TOPTf2N enables

5 eq LiTf2N

Acetone, 23 oC24 h

PCl PTf2NTOPClT (oC)

TOPTf2NT (oC)

2IL photocuring

Tm (oC) Tm (oC)87 < -90

hv

Mask projection micro-stereolithographyachieves well-defined 3D objectsachieves well defined 3D objectsSpecifications:Build Volume: 6 mm x 8 mm x 36 mmmm Resolution: 10-30 micronsLayer Thickness: 25 micronsBuild Rate: resin dependant

ComputerBuild Rate: resin dependant

Light Source Conditioning

OpticsMirror

PhotopolymerContainer

Linear Actuator

8 mm tall Hokie Bird

3D Printer: UV LED 365 nm, build surface intensity 5 mW/cm2, Digital micro image device 1080 p

C&E News, December 2014

X-Ray microCT reconstructs poly(PEGDMA90-co-TOPTf2N10) 3D cones to reveal reproducibility of CAD designs object

OO

x z

2D x-rayrotation

t

x-ray source

O

OO

PTf2N

MPµSL

2D x-ray detector

stageO

y

MicroCT: SkyScan 1172, 180O scan, 0.4O step

X-Ray microCTCAD Design MicroCT Image

SEM images of 3D hyperboloid reveals structural definitionstructural definition

0.5 mm1 mm

SEM: NEO Scope JCM 5000

Polyester cylinders provide structural advantages in tissue-engineered scaffolds

Inner layer:Endothelium

Middle layer:Smooth muscle & elastic tissue

Outer layer:Elastic and collagen fibers

llumen

SEM: NEO Scope JCM 5000

SFC-ELSD allows for high sensitivity oligomer separationoligomer separation

2 750 R

8 000

9.000

10.000

Range: 11Area

1.500

1.750

2.000

2.250

2.500

2.750

5.84922.57

7.58334.69

m=1

m=2

3

Species Molecular Weight (g/mol)

6.000

7.000

8.000

LSU

0.000

0.250

0.500

0.750

1.000

1.250

8.64150.88

9.3471.41

9.8539.05 10.20

31.86 10.6018.40

m=3m=0 495

m=1 2813Etc…

LSU

3.000

4.000

5.000

5.84

5.00 6.00 7.00 8.00 9.00 10.00 11.00

-0.250 m=2 5131

m=3 7450

m=4 9768

0.000

1.000

2.000922.57

7.58334.69 8.64

150.88 10.2031.86

m 4 9768

*Peaks assumed to be oligomers with increasing number of repeat units

Time-0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00

0.000

17

Aquity UPC2 SFC-ELSD, in collaboration with Dr. Mehdi Ashraf-Khorassani

Swiderski, K. W. et. al. Ind. Eng. Chem. Res. 2004, 43, 6281-6284.

Initial polymerization attempt, but serendipitous cyclic ionic liquids formp y q

Formation of highly favored six-membered ring

Theoretical m/z: 425.1583 g/molExperimental m/z: 425 1564 / l

membered ring results in quantitative yields

N i ifi t 425.1564 g/molNo significant oligomerization

Hemp, S.T. et al. Polymer Chemistry 2013, 4(12), 3582-3590. 18

APC reveals the presence of cyclics in polycondensation reactionspolycondensation reactions

Column Set:450 Å x 150 mm 2 Low M

Scal

e

200 Å x 150 mm200 Å x 150 mm

2 Low MwPeaks

mal

ized

SN

orm

1 5 2 2 5 3 3 5 4 4 5 5 5 5 6

Waters® ACQUITY APC, RI Detector, THF, 1.0 mL/min flow rate, XT Columns 19

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

Time (min)

Altering column set to smaller pore sizes, low molecular weight peaks are resolvedlow molecular weight peaks are resolved

Column Set:450 Å x 150 mm

cale

200 Å x 150 mm45 Å x 150 mm

mal

ized

Sc

Nor

m 5 Low MwPeaks

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

Waters® ACQUITY APC, RI Detector, THF, 1.0 mL/min flow rate, XT Columns 20

Time (min)

Using smallest column set, low molecular weight peaks are fully resolved, possibly cyclicsp y , p y y

Column Set:45 Å x 150 mm

Å

cale

45 Å x 150 mm45 Å x 150 mm

aliz

ed S

c

5 Low Mw

Nor

m Peaks

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

Waters® ACQUITY APC, RI Detector, THF, 0.8 mL/min flow rate, XT Columns 21

Time (min)

Aqueous SEC elucidated the presence of oligomeric cyclics in certain compositionsoligomeric cyclics in certain compositions

2p,2-cyclic6p,4-ionene pre-dialysis6p 4-ionene post-dialysis

ensi

ty

6p,4 ionene post dialysis

ve R

I Int

eR

elat

iv

Aq. SEC RI, 54/23/23 H2O/MeOH/AcOH 0.1 M NaAc 22

20 22 24 26 28 30 32 34 36Elution Time (min)

Absolute molecular weights determined using aqueous SECusing aqueous SEC

Hemp, S. T.; Zhang, M.; Tamami, M.; Long, T.E. Polymer Chemistry 2013.y y

IoneneMn

(kg/mol)a

Mw

(kg/mol)a PDIbdn/dc

(mL/g)c Cyclics?b(kg/mol) (kg/mol) ( /g)

4P,4 17.9 24.0 2.36 0.225 Yes (10 ring)

4P,6 15.3 18.2 2.34 0.224 Yes (12 ring)

6P,4 16.1 18.6 2.00 0.224 Yes (12 ring)

6P,6 20.6 27.2 2.51 0.213 No (14 ring)

2P 12 10 7 12 4 1 84 0 210 No (16 ring)2P,12 10.7 12.4 1.84 0.210 No (16 ring)

4P,12 23.6 28.4 2.07 0.205 No (18 ring)

6P,12 15.3 19.6 2.05 0.201 No (20 ring)

aAq. SEC MALLS, 54/23/23 H2O/MeOH/AcOH 0.1 M NaAc; bAq. SEC RI, Relative 23

12P,12 18.8 19.5 1.31 0.191 No (26 ring)

Molecular weight increased during phosphonium ionene polymerizationphosphonium ionene polymerization

115 min30 min

0 6

0.8

Inte

nsity 45 min

60 min90 min

Increasing molecular weight with time

0 4

0.6

aliz

ed L

S I

120 min180 min240 min360 i

0.2

0.4

Nor

ma 360 min

480 min1440 min

022 24 26 28 30 32 34 36

Aq. SEC MALLS, 54/23/23 H2O/MeOH/AcOH 0.1 M NaAc

22 24 26 28 30 32 34 36Elution time (min)

Kinetic analysis confirmed expected step-growth kinetics for phosphonium ionenesgrowth kinetics for phosphonium ionenes

Recall Xn = 1/1‐p

Aq. SEC MALLS, 54/23/23 H2O/MeOH/AcOH 0.1 M NaAc 25

Hemp, S. T.; Zhang, M.; Tamami, M.; Long, T.E. Polymer Chemistry 2013.

Acknowledgments Dr. Chris Williams and the DREAMS Lab for collaboration with 3D printing Dr. Mehdi Ashraf-Khorassani for his help with UPC2 SFC-ELSD

Thank you for Your Attention!Thank you for Your Attention!