Polymers and Supercritical Fluids

Transcription

1 Polymers and Supercritical Fluids Steve Howdle

2 View Cell

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4 Pressure either a liquid, nor a gas, but a combination of both! P c Solid Liquid Supercritical Region Critical Point Vapour Temperature T c

5 Polymers and scc 2 Green Solvent No Solvent Residues C 2 inert Inexpensive Novel Polymer Processing

6 Dispersion Polymerisation in scc 2? Monomer soluble homogeneous I. N.. I 2I + N I 2 Polymer insoluble - precipitates -

7 Dispersion Polymerisation in scc 2? Good anchoring to particle Polymer - philic Section of high solubility C 2 - philic J.M. DeSimone 1994 Si n Si

8 Dispersion Polymerisation in scc 2

9 How do we do the experiments?

10 Modular Clamp System Probe

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13 Controlled Dispersion Polymerisation in scc 2 ATRP (PMMA) - DeSimone/ Matyjaszewski, 1999 NMP (PSTY) - Aldabbagh /kubo 2005 RAFT kinetics - Buback / Beuermann 2005 Reversible Addition Fragmentation chain Transfer Living microparticles?

14 Why is Controlled Polymerisation Useful? Formation of copolymers Controlled composition Controlled MW Morphology Polymer A Polymer B

15 How? Monomer Kris Thurecht Andrew Gregory 2006 PDMS-MA surfactant RAFT + AIBN N S S Si n Si

16 Controlled Dispersion Polymerisation MMA CH 3 = methyl methacrylate (MMA) CH 3 Thurecht, K.J et al Macromolecules, 2007, RAFT-mediated Free flowing powder

17 Monitoring Reactions Sampling Unit Remove a sample

18 Polymer Characterisation Conv. M n PDI M th

19 The RAFT Mechanism I. N.. I 2I + N I 2 radicals interact with monomer = Monomer G. Moad, E. Rizzardo, S. H. Thang et al., Macromolecules, 1998, 31,

20 The RAFT Mechanism I. S S R.. Polymer chain or R group can be lost Z Coordination of polymer fragment produces stabilised intermediate G. Moad, E. Rizzardo, S. H. Thang et al., Macromolecules, 1998, 31,

21 The RAFT Mechanism I. S. Z Polymer chain continues to propagate R S. With this stabilised intermediate either polymer chain is able to leave G. Moad, E. Rizzardo, S. H. Thang et al., Macromolecules, 1998, 31,

22 WHY does RAFT work for dispersion polymerisation? S CN S S CN S S S CN Gas like C 2 S S CN H Plasticised polymer Mobility RAFT agent active

23 Block Copolymers? Polymerisation of MMA Inject second monomer

24 Phase Separation? D p = mm

25 Mariana Beija & James Jennings Nanostructured particles PMMA << P4VP PMMA P4VP 200 nm 200nm

26 Polymer Synthesis scc 2 dispersion polymerisation of block copolymers Controlled Nanostructured Microparticles 200nm

27 200 Load oxide component into just one domain????nostructured particles 200 nm

28 Device Manufacture Assembly of 3-D array and inorganic templating Functional dye sensitised solar cell device

29 PMMA-b-PS Broad Range of Monomers N PMMA-b-PVP n m n m H n S S S C 12 H 25 N n m PMMA-b-PBzMA n m PMMA-b-PDMA N hard / soft hydrophilic/hydrophobic n m PMMA-b-PDMAEMA

30 Block Copolymer Phase Diagram S C L C S N- Degree of Incompatability G f- Volume Fraction Miscible Region

31 N- Degree of Incompatability Sphere Cylinder No morphology f (PMMA) = 0.38 Lamellar Cylinder Sphere PMMA-b-PBzMA LAM GYR? No morphology f (PMMA) = 0.51 f (PMMA) = 0.59 f (PMMA) = kg/mol n m f- Volume Fraction 100% PMMA

32 Thin Film Study Collaboration with T. Higuchi, Univ Kyushu + THF, - THF f (PMMA) = 0.51 Thermal Annealing n m Spherical Cylindrical Gyroid Lamellar Gyroid Cylindrical Spherical

33 N- Degree of Incompatability Sphere Cylindrical PMMA-b-(P4-VP) Lamellar Gyroid Cylindrical Sphere Miscible Region 500nm N f- Volume Fraction n m f (PMMA) = 0.5

34 N- Degree of Incompatability Sphere Cylindrical Lamellar PMMA-b-(P4-VP) Gyroid Cylindrical Sphere Miscible Region 500nm N f- Volume Fraction n m f (PMMA) = 0.25

35 Proving the C 2 Effect- Thin Film Study Lamellar + THF, - THF f (PMMA) = 0.25 N Chloroform Vapour Annealing n m Cylindrical Spherical Cylindrical Gyroid Lamellar Gyroid Cylindrical Spherical

36 TEM- PMMA-b-PS n n No Stain Cylinders not lamellae PMMA-30K-b-PS-30K 200 nm

37 C 2 Effect on Phase Behaviour? PMMA PSt Δ C2 Absorption Reaction Density J. H. Aubert / Journal of Supercritical Fluids I1 (1998) 163-l 72 S.G. Kazarian J. Am. Chem. Soc., Vol. 118, No. 7, 1996

38 In-situ SAXS Analysis

39 Scattering Studies - Structure Evolution?

40 In situ SAXS

41 In-situ SAXS Analysis PMMA-b-PBzMA M n = 35900, Ð = I / arb.units q / nm -1

42 Supercritical Polymerisation scc 2 RAFT / Dispersion Living Particles Nanostructured Morphology Control

43 Are we limited to silicones and fluoropolymers for stabilisers? Si n Si Soluble hydrocarbons?

44 Pressure / psi Cloud Point Curves 5000 PEC-PPG (polyether carbonate-polypropylene glycol) 3000 PDMS -MA PFPE Temperature / o C

45 Solubility in C 2 Hydraulic Variable Volume View Cell

46 Measuring Solubility in C 2 Hydraulic Variable Volume View Cell Constant Temperature Screen Hydraulics C 2 + polymer Rear Sapphire Front Sapphire

47 Measuring Solubility in C 2 Hydraulic Variable Volume View Cell Constant Temperature Screen Hydraulics Polymer Dissolved single phase

48 Measuring Solubility in C 2 Hydraulic Variable Volume View Cell Constant Temperature Screen Hydraulics Cloud Point

49 Measuring The Cloud Point

50 Lee, H. ; et al JACS 2008,130, ; Lee, H.; et al Macromolecules 2010, 43, Birkin, N. A.; Polymer Chemistry 2011, 2, ; Park, E. J.; et al Polymer 2011, 52, Controlled Synthesis of Hydrocarbon Stabilisers Harry Lee, Natasha Birkin, Nic Arrowsmith, Eun Ju Park Xanthate H 2 C CH 3 S Vinyl Acetate + AIBN 65 C S C H2 H CH 3 n C H2 H m S tbu S C H 2 tbu PVAc-r-PVPi-X Vinyl Pivalate

51 Poly (Vinyl Acetate) Poly (Vinyl Pivalate) * H H H Good Solubility in scc 2 Electrostatic interaction of Carbonyl group of Acetate High Molecular Weight- Insoluble n * C * tertiary butyl group - increase solubility in scc 2 10, 000 g/mol n * H 3 C H 3 C CH 3 Molecular Weight

52 Pressure (psi) Phase Behaviour in scc 2 + NVP PVAc-X PDMS-mMA Temperature ( C)

53 Pressure (psi) Phase Behaviour in scc 2 + NVP PVPi-X PVAc-X PDMS-mMA Temperature ( C)

54 Pressure (psi) Phase Behaviour in scc 2 + NVP PVPi-X PVAc-X PVAc-PVPi-X (72:28) PDMS-mMA Temperature ( C)

55 Pressure (psi) Phase Behaviour in scc 2 + NVP PVPi-X PVAc-X PVAc-PVPi-X (10:90) PVAc-PVPi-X (24:76) PVAc-PVPi-X (16:84) PDMS-mMA PVAc-PVPi-X (44:56) PVAc-PVPi-X (72:28) Temperature ( C)

56 Successful Dispersion Polymerisation PVP [Poly(vinylpyrollidone)] in scc 2 H 2 C CH 3 Xanthate S Anchor Vinyl Acetate + AIBN 65 C S C H 2 H CH 3 n C H 2 H m S tbu S C H 2 tbu PVAc-r-PVPi-X Vinyl Pivalate

57 Superhydrophobic Surfaces Spraying of soluble compounds from rapidly expanding C 2 Charlotta.Turner@chem.lu.se, Lund University, Department of Chemistry,

58 Examples of polymer-coated surfaces PVAc-PVAc 9.5 kda PVAc-PVAc 20.6 kda SEM 35 θ A =132 θ A =164 PVAc-PVAc 9.5 kda PVAc-PVAc 20.6 kda vaskainen et al., J. Supercrit. Fluids, 2013, 77,

59 Enzyme Mediated Polymerisation of -Caprolactone n -CL solvent H Novozyme H n poly-cl In Toluene: T = 70 ºC, t = 4 h conv. = 86 % Novozyme 435: Lipase B from Candida antarctica supported on a macroporous acrylic resin (10 wt% enzyme) M n = 40,000 pdi = 1.7 Gross, Biomacromolecules 2000, 1, 133.

60 Technical Hitch! Freeze down the autoclave with acetone / dry ice before venting Pressure drops to atmospheric pen vessel / sublimation of dry ice

61 Plasticisation 37 C Poly(lactic acid)

62 High Pressure Rheology Anton Paar Physica Rheometer MCR 301

63 Viscosity reduction under C 2 : PCL 10 kda 80 C 96% P R E S S U R E S. Curia et al., In preparation,

64 Viscosity reduction under C 2 : PCL 80 kda 95% 80 C P R E S S U R E S. Curia et al., In preparation,

65 Nanocomposites C 2 -induced polymer plasticisation Blends scc 2 Modification Polymer chains C 2 molecule Lower viscosity Lower melting point... and so on! Avoid high temp & toxic organic solvents! 65

66 utline Intro Results Next Steps Viscosity of PCL under C 2 and N 2 80 C S. Curia et al., In preparation,

67 Lipase catalysed synthesis of poly(efa) in C 2 9, 10-epoxy-18-hydroxyoctadecanoic acid (EFA) uter bark of birch C bar, 85 o C Novozym 435 Selective reaction! Poly(9, 10-epoxy-18-hydroxyoctadecanoic acid) (Poly(EFA))

68 Lipase catalysed synthesis of poly(efa) in C 2 a b c Acetone a b c

69 Lipase catalysed synthesis of poly(efa) in C2

70 Lipase catalysed synthesis of poly(efa) in C 2 9, 10-epoxy-18-hydroxyoctadecanoic acid (EFA) Low Temperature Water Removal H -n H 2 0 CH 7 6 C psi, 85 o C, 24 h Novozym 435 H 7 6 C 7 6 C 7 n 6 Poly(9, 10-epoxy-18-hydroxyoctadecanoic acid) (Poly(EFA)) CH

71 C 2 IN C 2 and Water UT 60 ml Vessel

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73 scc 2 1 litre scale

74 Supercritical Polymerisation scc 2 RAFT / Dispersion Living Particles Nanostructured Morphology Control Enzymes & Renewables

75 View Cell

76 Plasticisation 37 C Poly(lactic acid)

77 Supercritical Mixing C 2 C 2

78 Supercritical Mixing C 2 C 2 Efficient Agitation

79 37 C Foaming

80 Supercritical Fluid Mixing Critical Mix 10 to 100 μm particles Dry Powder Protein Rapid Release through orifice Porous scaffolds Dry Powder Polymer (PLA, PCL, PEG) scc 2 autoclave Slow Release into mould

81 Preservation of Activity after Encapsulation and Release % ACTIVITY 100 Baseline activity before scc 2 Processing INSULIN BMP-2 RIB- NUCLEASE ANTIBDY CALCITNIN VANCMYCIN LYS- ZYME GM-CSF hgh VEGF 0 CHYMTRYPSIN MLECULAR MASS Wide range of biological materials processed using Critical Pharmaceuticals formulation process all showing excellent retention of activity

82 Drug Delivery Challenge: To find a robust, cost-effective method of delivering fragile, highly expensive proteins to the desired site of action over a prolonged period of time How: Mix a delicate drug molecule into a polymer particle Problem: Solvent residues; Damage to protein

83 Conventional: Double Emulsion DRUG AQUEUS PHASE RGANIC PHASE W/ EMULSIN AQUEUS PHASE W//W EMULSIN PARTICLES 1. Add drug to aqueous phase 2. Add aqueous phase to organic & mix 3. Add w/o emulsion to aqueous phase 4. Rapidly mix w/o/w emulsion 5. Evaporate organic solvent 6. Recover particles

84 Polymer Microparticles Whitaker, M. A.; Journal of Materials Science-Materials in Medicine 2011, 22 (8), Upton, C. E; Polymer , Baxendale, A.; International Journal of Pharmaceutics 2011, 413 (1-2), Kelly, C. A.; Advanced Functional Materials 2012

85 BioCity, Nottingham Founded 2002, 9 FTEs Human Growth Hormone

86 PLGA RG502H - ca. 30,000 kda PLGA microparticles - injectable sustained release formulation (hgh) Fractured Particle Density distribution q3* x(10 %) µm x(50 %) µm x(90 %) µm Param. 2 CP A <45um Q3(100 µm) % Cumulative distribution Q3 / % particle size / µm 0

87 Cumulative % Released Achieving Controlled Release for Challenging Drugs A three month anti-cancer treatment PLGA + drug? In vitro profiles Non-optimised formulation Time (Days) Can adding excipients allow controlled release profile to be achieved?

88 Cumulative % Released Achieving Controlled Release for Challenging Drugs CriticalMix formulation In vitro profiles Non-optimised formulation Time (Days) Adding excipients allows controlled release profile to be achieved

89 Cumulative % Released Achieving Controlled Release for Challenging Drugs CriticalMix formulation 1 CriticalMix formulation In vitro profiles Non-optimised formulation Time (Days) Adding excipients allows controlled release profile to be achieved

90 Injectability (Size, Shape, Distribution)

91 Injection Force

92 Lead Product: Human Growth Hormone (hgh) Disease target Paediatric growth hormone deficiency Adult growth hormone deficiency (HARS-Lipodistrophy) Worldwide sales = $2.5bn (2006) ff patent (branded and generic players) all once-a-day formulations, seeking product differentiation Unmet demand for a superior weekly/ 14d product High drug-loading and efficacy is complicated Abbreviated clinical trials process Copyright 2010 Critical Pharmaceuticals Limited

93 Subcutaneous Injection of Soluble hgh Soluble hgh Serum hgh ng/ml Injection of conventional Soluble hgh liquid (dissolved) hgh Target Serum Levels Time (Days) Copyright 2008 Critical Pharmaceuticals Limited

94 Controlled hgh Release in Primates Serum hgh ng/ml CriticalMix Formulation 1 CriticalMix Formulation 2 Soluble hgh Target Serum Levels Time (Days) Jordan, F et al J. Contr. Release , ; Kelly, C. A. et al Journal of Pharmaceutical Sciences ,

95 Critical Pharmaceuticals Products Growth Disorders in Children (Paediatric Treatment) CriticalMix Injectable sustained release technology Novel process to encapsulate drugs using supercritical C 2 Regulatory approved polymers

96 The GSK Carbon Neutral Laboratory Collaborative Development Carbon Neutrality Trial New Design Concepts New methods of working

97 Sustainable Chemistry Laboratories Infrastructure Challenges: Reduce Energy Costs, Lab Environment

98 Energy Efficient Features

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100 Wood Superstructure and Cladding

101 Groundbreaking Ceremony ctober 2013

102 The CNL site

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104 The CNL site the morning after the night before

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