This is a literature review for a study on the chemical resistance of 3D printable polymers. This literature review is initially targeted at liquid chemicals which can "attack" 3D printed polymers. In the future gas and plasma attack can be studied but for now it is out of the scope of this lit review.
==Introduction ==Our target is to find out what FFF (fused filament fabrication) 3D printing filaments tolerate the harsh chemicals that we use in semiconductor processing and other cleanroom processes. FFF was chosen as the preferred 3D printing method of choice due to its versatility, cost-effectivity and relative ease. 3D printing filaments are made from plastics by using additives (plasticizers and colorants), and the vendors rarely or ever provide the information on them to the customer. Therefore, it is not guaranteed that if a certain polymer tolerates, for example, HCl, 3D printed objects made from the same polymer could be used to make custom labware. We do not know if the 3D printing itself causes any changes to the chemical resistance of the polymers.
Polypropylene (PP) is a 3D printable polymer that can tolerate many chemicals, and the authors of articles listed below have made reaction vessels and microfluidics applications from it. But are we limited to PP? In this we need to search for clues in chemical compatibility charts, also found below.
We will experiment on 3D printing filaments and 3D printed objects by testing them in different chemicals and observing if they swell or dissolve.
==Sources == ====Journal Articles==== *Mark D. Symes, Philip J. Kitson, Jun Yan, Craig J. Richmond, Geoffrey J. T. Cooper, Richard W. Bowman, Turlif Vilbrandt & Leroy Cronin : [https://www.nature.com/articles/nchem.1313 Integrated 3D-printed reactionware for chemical synthesis and analysis], Nature Chemistry 4, 349–354 (2012), doi:10.1038/nchem.1313 **Reactionware for inorganic and organic synthesis **Reactionware: combines reaction vessel combined with reagents, catalysts, or control of shape to produce a desired result **Printed-in: catalysts and in-situ characterization **Modifying the geometry changes the outcome of the reaction **Robocasting of acetoxysilicone polymer (Loctite 5366): does not require heat, the material hardens quickly. **The properties of the material modified by e.g. mixing in conductive carbon black **Reusable reactionware, cleaved reactor could be glued shut again with the same material after cutting it open
*Philip J. Kitson, Mali H. Rosnes, Victor Sans, Vincenza Dragone and Leroy Cronin: [http://pubs.rsc.org/en/Content/ArticleLanding/2012/LC/c2lc40761b#!divAbstract Configurable 3D-Printed millifluidic and microfluidic ‘lab on a chip’ reactionware devices], Lab Chip, 2012, 12, 3267–3271. DOI: 10.1039/c2lc40761b **Millifluidic devices, made using PP (FFF, 3DTouch printer) **Properties of PP: robust, flexible, chemically inert, low cost **Three different millifluidic devices were made and demonstrated **Containers for solid materials were filled during printing and the printing was continued, which sealed the containers **Time and cost-effective method compared to traditional methods, single device takes only hours to build **Future interest: solvent compatibility
*Jennifer S. Mathieson, Mali H. Rosnes, Victor Sans, Philip J. Kitson and Leroy Cronin: [https://www.beilstein-journals.org/bjnano/articles/4/31 Continuous parallel ESI-MS analysis of reactions carried out in a bespoke 3D printed device], Beilstein J. Nanotechnol. 2013, 4, 285–291. doi:10.3762/bjnano.4.31 **3D printed tailored deviced linked to a mass spectrometer **3DTouch printer used to print thermoplastic PP **PP: low cost, robust, flexible, chemically inert **Screw fittings made from PEEK (harder than PP), provides a tighter seal
*Philip J. Kitson , Mark D. Symes , Vincenza Dragone and Leroy Cronin: [http://pubs.rsc.org/en/content/articlehtml/2013/sc/c3sc51253c Combining 3D printing and liquid handling to produce user-friendly reactionware for chemical synthesis and purification], Chem. Sci., 2013, 4, 3099-3103. DOI: 10.1039/C3SC51253C **Reactionware for a multi-step reaction was made, step control by rotating the device and letting gravity do the work -> need for pumps eliminated **Approaches from earlier articles combined: vessel was printed from PP, liquid-handling robot was used to functionalize the vessel **PP: melting point approx. 160°C, maximum working temperature 150°C **PP impermeable to hexane and diethly ether vapors, pressure build-up might need to be mitigated
*Bethany C. Gross, Jayda L. Erkal, Sarah Y. Lockwood, Chengpeng Chen, and Dana M. Spence: [http://pubs.acs.org/doi/abs/10.1021/ac403397r Evaluation of 3D Printing and Its Potential Impact on Biotechnology and the Chemical Sciences], Anal. Chem., 2014, 86 (7), pp 3240–3253, DOI: 10.1021/ac403397r **Common FDM/FFF materials: PC, ABS, PS, nylon, metals/ceramics **Many polymeric materials absorb small organic molecules, can also absorb organic or aqueous solvents. This can results in swelling of the bulk material
*Philip J. Kitson, Ross J. Marshall, Deliang Long, Ross S. Forgan, and Leroy Cronin: [http://onlinelibrary.wiley.com/doi/10.1002/anie.201402654/abstract 3D Printed High-Throughput Hydrothermal Reactionware for Discovery, Optimization, and Scale-Up], Angew. Chem. Int. Ed. 2014, 53, 12723 –12728 . DOI: 10.1002/anie.201402654 **Sealed monolithic reaction vessels from PP for hydrothermal synthesis. Array reactor, which allowed multiple experiments during one heating step. **Considerable savings achieved with 3D printed vessels compared to commercial alternatives **Another advantage: quick prototyping and ease of tailoring cheaply **FDM/FFF of PP **PP starts to soften at 150°C, some reactors burst in the heating due to pressure build-up. Reactors were safe for aqueous/DMF solutions over 72 hours at 140°C.
*Jayda L. Erkal, Asmira Selimovic , Bethany C. Gross, Sarah Y. Lockwood, Eric L. Walton, Stephen McNamara, R. Scott Martin, and Dana M. Spence : [http://pubs.rsc.org/en/content/articlehtml/2014/lc/c4lc00171k 3D printed microfluidic devices with integrated versatile and reusable electrodes], Lab Chip, 2014, 14, 2023-2032. DOI: 10.1039/C4LC00171K **3D printed devices, used in electrochemical detection. Printed using Objet Connex 350, material [http://global72.stratasys.com/~/media/Main/Files/SDS/Transparent-Materials/SDS-Object-VeroClear-RGD810-EU.pdf#_ga=2.176020706.1338903111.1510562312-2074105264.1508231826 VeroClear] (acrylate-based polymer). **Many electrode materials integrated in these devices for applications in e.g. detecting neurotransmitters, NO. **CADs and 3D printing: custom parts fitted into commercial equipment, rapid troubleshooting, easy to share designs with others.
*Philip J. Kitson, Stefan Glatzel, Wei Chen, Chang-Gen Lin, Yu-Fei Song,and Leroy Cronin: [https://www.nature.com/articles/nprot.2016.041.pdf 3D printing of versatile reactionware for chemical synthesis], Nat. Protocols, 2016, 11 (5), 920-936 **Describes the steps for making 3D printed reactionware **Open-source type development driving the growth of 3D printing **Advantages of 3D printing in chemistry: topology, geometry and composition of reactors precisely controlled **The versatility of 3DP materials is an advantage, but all of their applications impossible to describe in a single document **Extrusion-based methods (FFF/FDM) popular and economical, PLA and ABS most common materials **FDM applied in making fluidic reactors, but for the most part research focused on 3D printable materials, post-treatments, and batteries and LEDs **Limitations: epoxy- and acrylate-based materials used in SL not resistant organic solvents or extreme pHs. Similar problems for PLA and ABS. **FFF/FDM of nylon and PP more promising for chemical applications **Perfluorinated polymers difficult to print (small temperature window) and toxic. **Conventional FFF/FDM materials suitable for biological labware (water solutions, mild pH) **Choosing a material: inert to the desired chemistry. The author's choice: PP. Easy to print, good resolution and chemically inert. **PP attacked by very strong oxidizers, also by heated solvents (toluene) **Different grades of PP require different print settings (different melt profiles and flow)
====Chemical resistance charts ====
*[http://www.fmelighting.com/pdfs/Chemical_Resistance_Chart.pdf Rosemount analytical huge chart, resistance as a function of temperature]
*[https://www.curbellplastics.com/Research-Solutions/Technical-Resources/Technical-Resources/Chemical-Resistance-Chart Curbell Plastics]
*Schreirs, J. [https://books.google.fi/books?hl=fi&lr=&id=08y8kcvRS6AC&oi=fnd&pg=PA3&dq=fluoropolymer+chemical+resistance&ots=S-_sDXzXtG&sig=NDvFlfAP4WyGG9tPN5C6bSzYqUU&redir_esc=y#v=onepage&q=fluoropolymer%20chemical%20resistance&f=false Modern fluoropolymers.] Scheirs, J., Ed (1997): 32.
*Moiseev, Yu V., and Gennadiĭ Efremovich Zaikov. [https://books.google.fi/books?hl=en&lr=&id=8N2-fzAFw18C&oi=fnd&pg=PA1&ots=lIjOuftT7lsig=YtNNWguSLSGCe48AjzOpid_u_i0&redir_esc=y#v=onepage&q&f=false Chemical resistance of polymers in aggressive media]. Springer Science & Business Media, 1987.
*Seymour R.B., Carraher C.E. (1984) [https://link.springer.com/chapter/10.1007/978-1-4684-4748-4_10 Chemical Resistance of Polymers]. In: Structure—Property Relationships in Polymers. Springer, Boston, MA.
==Experimental== ===List of chemicals=== First, the resistance of 3D printable materials at least to the following solvents, acids and solutions is tested: * Deionized H2O * Isopropanol * Acetone * Hydrochloric acid (HCl), 37% * Ammonia (NH3), aqueous solution 25% * Hydrogen peroxide (H2O2), aqueous solution 30% * Nitric acid (HNO3) * Phosphoric acid (H3PO4) * Acetic acid, concentrated These chemicals are common chemicals used in many laboratories and many semiconductor processing steps, such as in the cleaning of silicon wafers. ===Chemical processes=== *Resist strip *RCA1 and RCA2 wafer cleaning processes, both in RT and 80°C *Al etch *Si etch *HF dip *BHF dip *Aqua regia *Piranha ==3D printing materials and their chemical properties ==
===ABS (Acrylonitrile butadiene styrene)===
One of the most used 3D printing filaments. Various vendors and available in multiple colors. Potentially more resistant to water and other chemicals than PLA.
*Chemical resistance of 3D printing materials
*Fused filament fabrication materials resistance
*Chemical resistance of polymers