Molecules to Manufacturing: Advancing the Additive Manufacturing Polymeric Materials Toolbox

Transcription

1 Molecules to Manufacturing: Advancing the Additive Manufacturing Polymeric Materials Toolbox Christopher B. Williams Associate Professor, Dept. of Mechanical Engineering, Virginia Tech Director, DREAMS Lab Associate Director, Macromolecules Innovation Institute SmartManufacturingSeries.com

2 The DREAMS VT Design for Additive Manufacturing DfAM decision support methodologies Cellular material topology design & optimization Process and Materials Research 3D Printing of novel photopolymers 3D Printing of metals and ceramics 3D Printing with nanocomposites Embedded electrical and actuation systems Education K-12 STEM utreach Undergraduate and graduate courses Informal learning environments Continuing education

3 VT Research Across the AM Process Advanced Materials for AM AM Processes Quality Assurance Application Decision Support Design for AM Design ptimization Metamaterial Design In-Situ Monitoring Cyber-Physical Security Workforce Development

4 DREAMS Lab Facilities Material Extrusion Metal/Ceramic/Sand Binder Jetting Multi-Material Jetting Polymer Powder Bed Fusion Multi-Modality Printing Mask Projection Vat Photopolymerization

5 Perception of Polymer AM?

6 FAA-approved ULTEM Air Duct

7 Industrial SLA Applications CAD QuickCast Pattern Metal Part

8 Industrial SLA Applications

9 2016 America Makes Smart Structures Innovation Sprint 1. Flex sensors 2. SMA wire + Thermistors 3. Patch antenna (copper tape) 4. USB Wi-Fi antenna + LED

10 Stratasys VeroWhite+ (stiff) HDT = 45 o C Strength = 50 MPa Young s Modulus = 2000 Mpa Stratasys TangoBlack+ (flexible) Strength = 0.8 MPa Elongation: 170% Jettable Photopolymers Performance Bass et al., Rapid Prototyping Journal, 2016 Moore & Williams, Rapid Prototyping Journal, 2014

11 Most high-performance polymers can t be printed 11

12 The polymers of the 1950s aren t necessarily well-suited for the advanced manufacturing processes of the 2020s.

13 Macromolecules Innovation Institute A virtual, university-wide materials program 60 faculty and 200 graduate students from Chemistry, Engineering, Physics, and Sustainable Biomaterials. Sponsored by over 20 industrial partners. M.S. and Ph.D. Degrees in Internationally Ranked and Interdisciplinary Macromolecular Science and Engineering (MACR) Program Please visit: Macromolecules and Interfaces Institute (MII)

14 New AM Polymers from Virginia Tech Extrusion: Water-soluble material for tailored dissolution Vat Photopolymerization: Polyimide Vat Photopolymerization: Polybutadiene Elastomers a b Material Jetting: Quantum dot inks Vat Photopolymerization: Biodegradable Polyester Vat Photopolymerization: Phosphonium Ionic Liquid Macromolecules and Interfaces Institute (MII)

15 Summary (in advance) AM is on the verge of an inflection point in the availability and quality of polymeric AM materials. Just as our products must be redesigned for effective use of AM, so must our materials. Polymers can be tuned for AM processing -- if the underlying process-structure-property relationships are established. Integrated design of the AM process, material, and product are needed to achieve anticipated breakthroughs. Macromolecules and Interfaces Institute (MII) 15

16 Molecules to Manufacturing Product Requirements Molecular Materials Design & Selection Synthesis Design Synthesis Characterization Design Analysis & Simulation Evaluation Product Geometric Design Manufacturing Process Selection Design Selection Modeling & Simulation Parameter ptimization Product Performance Analysis Material, Process, & Product Macromolecules and Interfaces Institute (MII)

17 ` Molecules to Manufacturing (M2M) Product Requirements Design Analysis & Simulation Evaluation Molecular Design & Synthesis Design Synthesis Characterization pportunity to realize breakthrough products via concurrent design of polymer chemistry, part geometry, and Product Geometric Design manufacturing process. Manufacturing Process Design Selection Modeling & Simulation Parameter ptimization Product Performance Analysis Material, Process, & Product Macromolecules and Interfaces Institute (MII) 17

18 M2M: Tailored Dissolution with Actives ` Product Requirements Molecular Design & Synthesis Water soluble (<10 min) Incorporation of actives (Max temp 80C) 3D printable (desktop material extrusion Design Analysis & Simulation Evaluation Product Geometric Design Manufacturing Process Design Selection Modeling & Simulation Parameter ptimization Product Performance Analysis Material, Process, & Product Macromolecules and Interfaces Institute (MII) 18

19 The Material: Sulfonated PEG Advantages: PEG is readily water soluble Bioinert Sulfonate group: Potential to stabilize actives Lowered melting point Charge interactions for enhanced mechanical properties 4K SPEG 8K SPEG Macromolecules and Interfaces Institute (MII)

20 Additive Manufacturing Extrusion Process Parameters Extrusion temperature Nozzle diameter Drawing speed Filament Extruder Extrusion temperature Bed temperature Filament feed rate Nozzle speed Extrusion AM Macromolecules and Interfaces Institute (MII) 20

21 Extrusion AM Material Parameters T g & T m Viscosity as f(shear rate, T) Stiffness & Strength Thermal Conductivity & Expansion Surface Tension & Hydrophilicity Macromolecules and Interfaces Institute (MII) 21

22 Poly(PEG8k-co-CaSIP) exhibits favorable viscosity for extrusion 3D printing Minimal shrinkage No Coalescing Can bridge large gaps 10mm gap shown No strings between gaps ~55 o angle for 0 Support * Note: Images do not represent actual color. All products are white in color. Macromolecules and Interfaces Institute (MII)

23 Blue Value (#) Tailored Dissolution via Geometry mm Wall mm Wall mm Wall ,000 4,000 6,000 8,000 10,000 Time (s) Macromolecules and Interfaces Institute (MII)

24 What makes a material printable? How to tailor a material for AM? How to tailor an AM system for a material? Macromolecules Innovation Institute (MII)

25 What makes a material printable? How to tailor a material for AM? How to tailor an AM system for a material? Macromolecules Innovation Institute (MII)

26 Traditional Stereolithography Resin Design Requires a photocrosslinkable site Inert monomer core with photocrosslinkable moiety Acrylates ; epoxies ; vinylethers Aliphatic polymers and oligomers T d < 400 o C; T g < 100 o C Constrained to thermosets Process constrains allowable resin viscosity Vat photopolymerization: < 3-5 Pa s Material Jetting: < 0.2 Pa s

27 Polyimides are used in many extreme and high-value applications perating temp. up to 450 C Elastic modulus 2+ GPa Thermal, electrical, radiation resistance Satellite sheathing Flexible circuits Aerospace & military Medicine & cryogenics High vacuum environments 2D form factor

28 All-Aromatic Polyimides: very difficult materials to process Difficult to process pseudothermoplastics No melt flow can t be melt processed Resistant to all organic solvents Poly(4,4 -oxydiphenylene-pyromellitimide) (PMDA-DA) known commercially as Kapton by DuPont Some are only produced as films (e.g. Kapton ) Complex shapes are often impossible

29 How do we make an all-aromatic polyimide printable via SLA? PMDA-PDA (Kapton ) We can t just put acrylate groups on the polyimide Not soluble in any organic solvents Polyamic acid Add acrylate groups to its precursor, polyamic acid, which is soluble in NMP Allows us to print the polymer, not the monomer! 29

30 Fabrication strategy: print PADE, a polymeric organogel B NH NH = n NH Light Blocker Polymer with MW = 49,000 g/mol soluble precursor of polyimide polyamic diacrylate ester =(PADE) NH Light Blocker n Photoinitiator soluble precursor of polyimide polyamic diacrylate ester (PADE) 15 wt.% PADE in NMP 2.5 wt.% PP (Photoinitiator) 1.5 wt.% 4-nitrophenol (Light Blocker) hν ( nm) Dissolved PADE 15 wt.% PADE in NMP 2.5 wt.% PP (Photoinitiator) 1.5 wt.% 4-nitrophenol (Light Blocker) hν ( nm) NMP 3D 3D printer NH NH Dissolved PADE n NH NH n NH NH n NH NH 3D printed structure n insoluble, insoluble, crosslinked PADE crosslinked PADE Hegde et al., Advanced Materials (2017) 30

31 rganogel Structures of Polyimide Precursor B 1 mm 1 mm 1 mm

32 Dissolved PADE 15 wt.% PADE in NMP 2.5 wt.% PP (Photoinitiator) 1.5 wt.% 4-nitrophenol (Light Blocker) hν ( nm) Post processing: NH rganogel to Polyimide Close ring NH n Close ring NH NH n n crosslinked PADE NH NH Wash in GBL/ace remove NMP at 2 - NMP extract residual N 1. Wash in GBL/acetone, airunder dry vacuum overnight, extract residual NMP under vacuum at 160 C for 1 h Thermal imidizat in N2 furnace - Crosslinkers insoluble, crosslinked Crosslinked PADE PADE 2. Close ring and create polyimide by thermally imidizing in a furnace at 350 C in N2 for 2 h N N PMDA-DA polyimide PMDA-DA (Kapton )polyimide All carbons are aromatic Adapted from Hegde et al., Advanced Materials (2017) n 32

33 Modulus: 2.2 GPa Strain at failure: 9.5 % Measured properties of printed PMDA-DA similar to Kapton film Tensile strength: 79 G MPa Modulus at 300 C: 1 GPa Decomposition: 600 C G The highest temperature material 3D printed using SLA B G wet 25 o C!32!%!! 60 o C 42!%!! wet 25 o C!32!% wet 25 o C!32!%!! 60 o C 200 o C!47!%!! 300 o C!49!%!! 350 o C!53!%!! 33

34 Quantifying shrinkage during post processing of printed PADE Shrinkage is large, but near-isotropic 100% 80% 100% 100% 60% 40% 20% 44% 42% 36% 30% 0% As Printed Dried Imidized X-Y Z 34

35 What makes a material printable? How to tailor a material for AM? How to tailor an AM system for a material? Macromolecules Innovation Institute (MII)

36 Continuous Fiber Composites for Extrusion AM Patented dual-extrusion process Injection of TLCP into matrix yields continuous streams of TLCP encapsulated in thermoplastic matrix Dr. Don Baird, VT

37 Large-Scale 6-DoF Robotic Extrusion Mid-scale (3 ft.) 6 DoF Robotic Arm VT DREAMS Lab Large-scale (10 ft.) Robotic Arm VT School of Architecture

38 ut of Plane Printing 38

39 3-axis 6-axis Reinforced Composite skinning via 6-DoF Extrusion Yield Strength 39 Kubalak et al., SFF 2017

40 Summary We are starting an inflection point in the availability and quality of polymeric AM materials. Just as our products must be redesigned for effective use of AM, so must our materials. Polymers can be tuned for AM processing -- if the underlying process-structure-property relationships are established. Integrated design of the AM process and the material and the product are needed to achieve anticipated breakthroughs. Macromolecules and Interfaces Institute (MII) 40

41 DREAMS Lab Acknowledgements Nicholas Chartrain Viswinath Meenakshisundaram Don Aduba Logan Sturm Saish Tedia Yun Bai Joseph Kubalak Nick Meisel (Penn State) Jacob Moore (Penn State Mont Alto) Phil Lambert (DiSanto Technology, Inc.) Earl Campaigne (National Instruments) The Long Group Maruti Hegde (UNC-Chapel Hill) Justine Sirrine Kevin Drummey Philip Scott Allison M. Pekkanen (Booz Allen Hamilton)

42 Sponsors National Science Foundation Air Force Research Laboratory Air Force ffice of Scientific Research Virginia Center for Innovative Technology VT Institute for Critical Technology & Applied Science VT Institute for Creativity, Arts and Technology Honeywell National Security Campus Electro-Mechanical Corporation Macromolecules Innovation Institute America Makes Macromolecules Innovation Institute (MII)

43 Thank you! Christopher B. Williams 1 mm Macromolecules Innovation Institute (MII)