Environmentally Degradable Plastics. Douglas D. Keller Research Specialist Presented to Plastic Shipping Container Institute April 10, 2006

Transcription

1 Environmentally Degradable Plastics Douglas D. Keller Research Specialist Presented to Plastic Shipping Container Institute April 10, 2006

2 Disclaimer All information presented is based on published information and literature searches. No laboratory evaluations have been performed on any of the environmentally degradable polymers. Lyondell Chemical Company makes no expressed or implied recommendation as to the suitability of environmentally degradable polymers for any application. References for specific statements can be found at the end of the presentation. 2

3 Outline Market drivers Environmentally degradable plastics (EDP) Definitions Classes Properties Applications Conclusions We create sustainable business value by being a preferred solutions provider to our customers. 3

4 Raw Material Economics Making EDP More Economically Viable Note: A unit of each raw material is not equal to the other in terms of energy or polymer produced. Corn-Gulf Ports Natural Gas-Gulf Ports 8.00 $/bu or $/Mbtu Sep-99 Mar-00 Sep-00 Mar-01 Sep-01 Mar-02 Sep-02 Mar-03 Sep-03 Mar-04 Sep-04 Mar-05 Source: USDA & CMAI Month 4

5 Market Drivers/Restrictors of Environmentally Degradable Polymers (EDP) Raw material price increases and instability (driver for partnership between Wal-Mart and NatureWorks) Legislation in EU and Asia (Japan & China) mandates waste reduction burden placed on packaging producers Asian & European companies leading novel polymer creation EDP are market disrupters new producers will come forward to produce the materials. Legislation in Canadian Provinces, California & Oregon putting burden on packaging producers and users Waste legislation driving industry to search for higher value applications for recycled material 5

6 California 2003 Overall Disposed Waste Stream Mixed, 1.1% Special, 5.1% House. Haz. Waste, 0.2% Const. & Dem., 21.7% Paper, 21.0% Glass, 2.3% Metal, 7.7% % by weight Organic, 30.2% Electronics, 1.2% Plastic, 9.5% Source: California Integrated Waste Management Board 6

7 California 2003 Plastic Waste Survey PETE, 0.5% Remainder/Composite, 2.2% HDPE, 0.5% Misc. Plastic Cont., 0.5% Trash Bags, 1.0% Durable Items, 1.4% T-Shirt bags, 0.4% Comm. & Ind. Pkg, 0.7% Values are % by weight of total waste stream. Other Film, 2.1% Film Products, 0.2% Source: California Integrated Waste Management Board 7

8 California 2003 Plastic Waste Survey Rigid Plastics Packaging Container Composition of Overall Disposed Waste HD Pails, 0.14% APC 3-7 Other, 0.05% PET Bottle, 0.29% APC 3-7 Clamshell, 0.06% APC 3-7 Bottles, 0.02% Values are % by weight of total waste stream HD Other, 0.02% PET Other, 0.05% HD Colored Bottles, 0.12% HD Nat. Bottles, 0.12% Source: California Integrated Waste Management Board 8

9 EDP Degradation Mechanisms Biodegradable Compostable Hydro-biodegradable Photo-biodegradable Bioerodable 9

10 Definition of Biodegradable ASTM 1 defined biodegradable as: capable of undergoing decomposition into CO 2, methane, water, inorganic compounds or biomass in which the predominant mechanism is the enzymatic action of micro-organisms, that can be measured by standardized tests, in a specified period of time, reflecting available disposal conditions. Biodegradation rates are highly dependent on thickness and geometry. Thick-walled articles such as plates and cutlery can take up to a year to biologically degrade. 2 Polyolefins must be < 5000 M w (wax) for microbial ingestion (pail grades ~80,000 M w ) 1 ASTM D d Standard Terminology of Environmental Labeling of Packaging Material and Packages (Discontinued 2002) 2 Australian Government Department of Environment and Heritage. 10

11 Definition of Compostable ASTM 1 defined a compostable material as: capable of undergoing biological decomposition in a compost site as part of an available program, such that the material (that is, feedstock) is not visually distinguishable and breaks down to CO 2, water, inorganic compounds, and biomass, at a rate consistent with known compostable materials. Typical composting conditions Time: 12 weeks Temp: > 140 o F 1 ASTM D d Standard Terminology of Environmental Labeling of Packaging Material and Packages (Discontinued 2002) 11

12 Definitions of Hydro- & Photo-Degradable Hydro- or photo-degradable polymers break down in a twostep process An initial hydrolysis or photo-degradation stage followed by further biodegradation ASTM 1 defined photo-degradable as capable of undergoing a significant loss of properties that can be measured by standardized tests after exposure to representative amounts of sunlight. 1 ASTM D d Standard Terminology of Environmental Labeling of Packaging Material and Packages (Discontinued 2002) 12

13 Definition of Bio-erodable Bio-erodable plastics degrade in two stages: First Stage non-biological disintegration Heat exposure (oxidative embrittlement) or UV exposure (UV aging) or Abrasion Second Stage micro-organism degradation Microbes are able to attack polymer chains at weak points Easier to attack and ingest when polymer chains are shorter 13

14 Classes 2 of Environmentally Degradable Plastics Biodegradable polyesters Biodegradable starch-based polymers Water-soluble polymers Photo-degradable polymers Controlled degradation masterbatches 2 Classification based on work performed for the Australian Department of Environment and Heritage by Nolan-ITU. 14

15 Biodegradable Polyesters Two classes of polyesters Aromatic (PET) Excellent mechanical properties Almost totally resistant to microbial attack Linear (polycaprolactone & polylactic acid) Reduced/poor mechanical properties Readily biodegradable when in contact with microbes Linear polyesters are sometimes blended with starches which are more hydrolytically stable 15

16 Biodegradable Polyester Polymers Polyhydroalkanoates (PHA) and copolymers (PHB and PHV) Produced by bacterial fermentation not commercial Claim PP-like properties; targeting cutlery, coated paper cups, bottle caps, foamed coffee cups, coffee lids, straws PHB + PHV + plasticizer films, IM, blow molding ADM & Metabolix have announced JV on PHA plant (100 M lbs) Poly-hydroxybutyrate-co-polyhydroxyhexanoates (PHBH) Fermented from sugars or fatty acids Nodax TM JV of Kaneka and P&G films & flexible applications in Europe Polylactide (PLA) Polymerization of lactic acid derived primarily from corn Cargill (NatureWorks) and others Nodax TM is a trademark of The Procter & Gamble Co. 16

17 PLA & PLA + Starch Polymers Blend with starch to increase biodegradability and reduce cost Blends tend to be brittle IM grades are certified for FDA food contact Applications Thermoforming Injection molding Injection stretch blow molding Good rigidity allows PLA to replace PS and PET in some applications Material must be dried 17

18 Comparison of NatureWorks PLA and Pail HDPE NatureWorks Property Density Melt Index (190,2.16) Tensile Yield Stress Tensile Yield Elongation N. Izod Impact Flexural Modulus PLA 3001D 1.24 g/cm g/10 min. 7,000 psi 2.5% 0.3 ft-lb/in 555,000 psi Standard Pail Grades g/cm g/10 min. 4,000 psi 9% 0.9 ft-lb/in 181,000 psi NatureWorks is a trademark of NatureWorks LLC. 18

19 Comparison of TERRAMAC (PLA) and Pail HDPE Property (ISO) Density Tensile Break Tensile Yield Bending Modulus Notched Charpy Impact Strength Heat 0.45 MPa TERRAMAC TE g/cm 3 50 MPa 2% 6,800 MPa 4.0 kj/m o C Standard pail Grade g/cm 3 > 13.6 MPa 9.3% MPa 6.5 kj/m 2 61 o C TERRAMAC is a trademark of Unitika Ltd. 19

20 Other Polyester Degradable Materials Polycaprolactone (PCL) Synthetic polymer with low melting point o F Blended with starch for foam trays, loose fill & film bags Aliphatic-aromatic copolyesters (AAC) Degradable with LDPE-type mechanical properties Blends with starch for blown and cling film Modified PET Addition of copolyesters to adjust physical properties and degradation characteristics Polybutylene succinate (PBS) Excellent mechanical properties hydro-degradable Blended with starch and adipate copolymers for mulch film, packaging film and flushable hygiene products Rigid target applications include cups, cutlery, razor handles and straws 20

21 Enpol TM (PBS) vs. Standard Pail Grade Property (ASTM) Melting Temp. Melt Index Density Tensile Break Break N. 23 C Enpol G o F 25 g/10 min g/cm psi 150% 0.2 ft-lbs/in Standard Pail Grade 263 o F 6.3 g/10 min g/cm psi 1780% 0.8 ft-lbs/in Enpol TM is a trademark of Polyval PLC. 21

22 Biodegradable Starch-Based Polymers Starch is a linear polymer (polysaccaride) and inexpensive Amylose linkage in starch is flexible and digestible For biodegradable polymers: Starch content: 10 90% For significant material breakdown: >60% starch At < 60%, non-starch polymer disintegrates into smaller fragments, but doesn t bio-degrade easily Polymer blend components Thermoplastic (PP, PE Novon TM ) Polycaprolactone (PCL a.k.a. Mater-Bi TM, Bioflex TM ) Polybutylene succinate (PBS) or polybutylene succinate adipate (PBSA) Polyvinyl alcohol (PVA a.k.a. Novon TM, Mater-Bi TM ) Novon TM is a trademark Novon Japan, Inc. Mater-Bi TM is a trademark of Novamont. Bioflex TM is a trademark of Biotech. 22

23 Uses of Starch-Based Polymers Thermoplastic Film, packing peanuts, take-away containers, foamed PS replacement, dog bones PCL Low melting (140 o F) & softening point (104 o F) limited to sheet and film applications, disposable molded articles PBS / PBSA Compatibilizers & plasticizers needed for >45% starch plastic sheet for thermoforming Polyvinyl alcohol Highly soluble in water foamed packing peanuts 23

24 Hydro-Degradable Polymers Polyvinyl Alcohol (PVOH) Does not biodegrade dissolves in water Generally used for film applications (incontinence items) Ethylene Vinyl Alcohol (EVOH) A copolymer of vinyl acetate and ethylene Used as an O 2 or hydrocarbon barrier as part of a multilayer structure Too expensive to be used on its own 24

25 Photo-Biodegradable Plastics Synthetic thermoplastic polymers plus Light-sensitive chemical additives or Light-sensitive copolymer or Catalytic metals Breakdown mechanism: Polymers chains break from UV exposure, and/or Physical degradation from wave action or abrasion on rocks Useful where littering on land or sea is an issue 25

26 Controlled Degradation Additive Masterbatch Added to non-degradable plastics to cause controlled degradation Catalytic transition metal compounds Cobalt stearate Manganese stearate Added at 1-3 wt% Additional cost over PE of 10-35% Higher amount leads to faster 3%, PE film has 95% weight loss after o F Degradation begins at material processing 26

27 Applications for Biodegradable Plastics (Australia Department of Environment & Heritage) Biodegradable plastics are well placed to substitute conventional plastics in low-weight, miscellaneous packaging applications that are not currently recycled. Examples: Coated paper (sandwich wrappers) Agricultural mulch film Shopping bags Food waste film and bags Consumer packaging material (bread bags, six-pack rings) Landfill cover film Cling wrap Fishing line, nets and bait bags 27

28 Global Sales Volume of Biodegradable Polymer (Fully Biodegradable Only) Application AAGR% Packaging Compost Bags Other Total Volume in M lbs. 1 Includes loose-fill packaging which constitutes two-thirds of the total. 2 Includes medical/hygiene products, agricultural, paper coatings, etc. Source is RP-175R Biodegradable Polymers, November 2005, Business Communications Co., Inc. in summary published in SPE Tech Focus. 28

29 Conclusions Multiple polymers available Most are suitable for flexible applications or articles requiring high stiffness & short-term use currently targeting PET and PS applications EDPs are market disrupters Suppliers will generally be outside current polymer supplier community Suppliers likely to be well-sourced in feedstocks (Cargill, ADM, etc.) Commercial viability hinges on technology and efficiency improvements Market penetration depends on conventional polymer pricing 29

30 References Slide 5-7: data from Slide 9: rate statement from Slide 10: D d was discontinued and not replaced by any standard. Similar definitions can be found in ASTM D The Federal Trade Commission has guidelines for environmental claims on products. Slide 10: Mw for microbial ingestion is theoretical. Controlled degradation additive suppliers indicate that some digestion occurs at 30,000 Mw but only on the ends of the polymer chains. Slide 17: PLA 3001D data from NatureWorks TM PLA Polymer 3001D injection molding processing guide; standard pail grade data based on Equistar testing of Alathon M5363. No calculation method listed for PLA3001D flexural modulus, M5363 data is 1% secant on compression molded specimens Slide 18: TERRAMAC data from All values except density based on ISO injection molded specimens. Bending modulus calculation for TE-8210 not specified, range for std. pail grade is 1% secant to chord modulus. Slide 20: EnPol data sourced from Slide 27: Source for data is RP-175R Biodegradable Polymers, November 2005, Business Communications Co., Inc. in summary published in SPE Tech Focus. 30