Vincentius Andrew Soesanto February 2 2015 CBE 555.

Vincentius Andrew SoesantoFebruary 2 2015

CBE 555

Manufacturing (degradable) polymers

• First emerged in Europe due to landfill capacity and poor public image of plastics

• In 2012, demand fraction was 55% for Europe, 29% for North America and 16% for Asia

• Total demand was speculated to rise from 269,000 metric tons in 2012 to 525,000 metric tons in 2017

• Primary uses include food packaging and food–service products

I. Biodegradable polymer market

‡(no author) – (Plastics News Report), 2013, Report: Biodegradable plastics demand growing 15% annually‡(no author) – 2006, Global biodegradable polymer market by application

• Primary components include PLA (47%) and starch–based polymers (41%)

• Nature Works: natural plant sugars PLA• Metabolix: switchgrass biodegradable polymers (using enzymes)• Compostability requirements:

1. Biodegradation

2. Disintegration

3. Non–toxicity• ISO 17088 requires at least 60% of biodegradation within 180 days

I. Biodegradable polymer market

‡(no author) – (Plastics News Report), 2013, Report: Biodegradable plastics demand growing 15% annually‡Talbot (2013), Plastic from Grass: Engineers seek a cheaper biodegradable polymer

I. Biodegradable polymer market

‡Hermans & Banholzer, January 22 2015, Lecture Notes

II. Manufacturing degradable polymers

II. Manufacturing degradable polymers

Anionic polymerization:

Initiators: strong bases like metal hydroxides / alkoxidesSolvents: must contain no protic impurities (e.g. , , etc)

‡Young & (2011), Introduction to Polymers, pp. 179 – 180

II. Manufacturing degradable polymers

Cationic polymerization:

Initiators: strong acids such as Solvents: non–polar (e.g. hexane) or very polar (e.g. methylene chloride) solvents

‡Young & (2011), Introduction to Polymers, pp. 174 – 175

II. Manufacturing degradable polymers

• Anionic more rigorous• Both are carried out:

– Low temperatures– Stainless steel units

Cationic v.s. anionic polymerization:

II. Manufacturing degradable polymers

Condensation polymerization:

• Small molecule by–products continuously removed using heating, drying agents, azeotropic distillation, imposing a partial vacuum or purging with an inert gas

• Interfacial polymerization used when possible

‡Young & (2011), Introduction to Polymers, pp. 23

II. Manufacturing degradable polymers

  Step–growth Controlled chain–growth

FundamentalThermodynamically controlled

Kinetically controlled

Number–average molecular weight,

Polydispersity index, (ranges btw. 1 and 2)

Step v.s. chain polymerization:

• is initial monomer concentration• is initial initiator concentration• is percent conversion of monomer

II. Manufacturing degradable polymers

Polymer (transport) properties:

• Non–Newtonian fluids (i.e. )

• Numerous mechanical (anisotropic) properties (e.g. stresses, elongational viscosity, tensile strength etc)

‡Bird, Stewart & Lightfoot (2008), Transport Phenomena, pp. 231 – 257

II. Manufacturing degradable polymersPolymer (transport) properties:

State Compound Thermal conductivity at ()

GasAirCarbon dioxide

LiquidAcetone 0.16MethanolWater

Solid

IronZincSodiumHDPELDPEPMMAPolypropylene

‡Engineering Toolbox

II. Manufacturing degradable polymers

Polymer (transport) properties:

High viscosity laminar flow poor mixing

Low thermal conductivity slow heat conduction

High viscosity + low thermal conductivity radial temperature gradient & trapped heat (viscous heating)

Rec.:

‡Bird, Stewart & Lightfoot (2008), Transport Phenomena, pp. 298 – 300

II. Manufacturing degradable polymers

Heat of polymerization:

MonomerTetrafluoroethyleneVinyl chlorideEthyleneVinyl acetateMethyl acrylateStyreneMethyl methacrylate

‡Middleman (1977), Fundamentals of Polymer Processing, p. 369

II. Manufacturing degradable polymersIn the industry:

• Reactor: tubular reactors with temperature control bath• Separator(s):• Extrusion or fiber spinning to extract solid• Filtration, evaporation or vacuum distillation to remove

remaining solvent• How to handle viscous heating:• Cooling jackets• Smaller diameter tubes• Suspension / emulsion polymerization

• How to prevent runaway reaction(s):• Temperature adjusted using heat exchange area• Conversion adjusted using initiator or inhibitor concentration

‡Middleman (1977), Fundamentals of Polymer Processing, pp. 385 – 386‡Rawlings & Maravelias (1994), Process Dynamics & Control: Laboratory Manual, pp. 135 – 137

Unit Operation Function

Dissolution Dissolving solid polymer (chips) in a solvent

ExtrusionPumping the polymer to produce a set of conditions (e.g. film thickness, temperature, linear speed, surface gloss etc)

CalenderingSqueezing of films between rolls for the purpose of thinning the film or imparting surface characteristics

Coating Coating another liquid on one side or both of a film

Drying Evaporating the solvent contained in the coating material

II. Manufacturing degradable polymers

Mechanical processing units:

‡Middleman (1977), Fundamentals of Polymer Processing, pp. 2 – 3

II. Manufacturing degradable polymers

Mechanical processing units (mixer):

‡Middleman (1977), Fundamentals of Polymer Processing, pp. 345

II. Manufacturing degradable polymers

• Made by mixing synthetic polymers (e.g. poly(lactide)) with starch or cellulose

• PLA made by Carothers (1932) and developed by DuPont:• Cargill Dow – solventless method with novel distillation• Mitsui and Toatsu – condensation with azeotropic distillation

Manufacturing biodegradable polymers:

Polymer Company Capacity (tons / year)

Poly(lactic acid) Cargill Dow LLC 140,000

Poly(ε-caprolacton) Union Carbide >5,000

Poly(ethylene terephthalate, adipate)

BASF 8,000

Master–Bi starch Novamont 20,000

‡Gross & Kalra (2002), Biodegradable Polymers for the Environment

III. Degradation

• Biodegradable polymer packaging and their contents are degraded together to CO2, CH4, water, biomass and other natural substances

• Enzymatic degradation by microorganisms• Non-enzymatic degradation (e.g. hydrolysis)

‡Merechal, F. (2003), Biodegradable plastics: View of APME‡Gross & Kalra (2002), Biodegradable Polymers for the Environment

III. DegradationNon–enzymatic pathway:

‡Mahanthappa (2014), Lecture Notes

III. Degradation

Enzymatic pathway:

‡Tokiwa, Calabia, Ugwu, & Aiba (2009), Biodegradability of Plastics

• Enzymatic binding followed by a hydrolytic cleavage• Polymers oligomers dimers monomers low boilers• PLA degraded using Amycolatopsis or Saccharotrix strains

(Williams proteinase K)

IV. Conclusion

References1. (no author) – (Plastics News Report), 2013, Report: Biodegradable plastics demand

growing 15 percent annually (27 January 2015, http://www.plasticsnews.com/article/20130422/NEWS/130429995/report-biodegradable-plastics-demand-growing-15-percent-annually)

2. (no author) – 2006, Global biodegradable polymer market by application, 2000-10, (27 January 2015)

3. Talbot, D. (2013), Plastic from Grass: Engineers seek a cheaper biodegradable polymer, MIT Technology Review Magazine

4. (no author) (2013), Biodegradable plastics demand to grow 15% annually to 2015 (27 January 2015, http://www.plastemart.com/Plastic-Technical-Article.asp?LiteratureID=1958&Paper=biodegradable-plastics-demand-to-grow-15-percent-annually-to-2015)

5. Patel, M. (2003), Do Biopolymers Fulfill Our Expectations Concerning Environmental Benefits, Kluwer Academic / Plenum Publishers, New York

6. Source: Mohan, A. M. (2010), Biodegradable polymers market to grow at 13% through 2014, GreenerPackage.com (27 January 2015, http://www.greenerpackage.com/bioplastics/biodegradable_polymers_market_grow_13_through_2014)

7. Hermans, I. & Banholzer B., January 22 2015, Lecture Notes, University of Wisconsin–Madison

References (continued)

8. Young, R. J. & Lovell, P. A. (2011), Introduction to Polymers, 3rd edition, CRC Press, Taylor & Francis Group, Boca Raton

9. Bird, R. B., Stewart, W. E & Lightfoot, E. N. (2008), Transport Phenomena, 2nd edition, John Wiley & Sons, New York

10. Engineering Toolbox

11. Middleman, S. (1977), Fundamentals of Polymer Processing, McGraw–Hill, Inc.

12. Rawlings, J. B. & Maravelias, C. T. (1994), Process Dynamics & Control: Laboratory Manual CBE 470, 3rd edition, pp. 135 – 137

13. Merechal, F. (2003), Biodegradable plastics: View of APME, Kluwer Academic / Plenum Publishers, New York

14. Gross, R. A. & Kalra, B. (2002), Biodegradable Polymers for the Environment, SCIENCE, VOL 297, www.sciencemag.org

15. Mahanthappa, M. K., September 2 2014, Lecture Notes, University of Wisconsin–Madison

16. Tokiwa, Y., Calabia, B. P., Ugwu, C. U. & Aiba S. (2009), Biodegradability of Plastics, Int J Mol Sci., 10(9), 3722 – 3742, doi: 10.3390/ijms10093722

17. Swift, G. (2003), Significance and implications of Green Polymer Chemistry, Kluwer Academic / Plenum Publishers, New York