James Schrader

1. Bioplastic Container Cropping Systems
Biodegradation of Biocontainers
in Soil and Compost
James Schrader - Iowa State University

2. BiodegradationBiodegradationBiodegradation
in Soilin Soilin Soil

3. Experimental Design

4. Degradation weight loss (%)
Round-2 Over Over
Container Material 6 months 1.5 years
Petroleum plastic (polypropylene) 0 k 0 j
PLA composite with
Soy 50% 45 c 47 c
Soy 33% 30 e 35 ef
DDGS 20% 11 i 14 i
Soy + DDGS 30/10 34 d 37 de
Soy + Lignin 30/10 26 f 28 gh
Lignin 20% 0 k 0 j
Protein (AR) 33 de 35 ef
Recycled PLA 0 k 0 j
PHA composite with
Soy 33% 86 b 100 a
DDGS 20% 47 c 94 b
Starch 10% (Met. P1008) 15 h 40 d
Cellulose (AR) 100 a 100 a
PolyAmide with
DDGS 30% 20 g 23 h
Lignin 30% 1 k 1 j
PLA 30% 0 k 1 j
Paper fiber
Uncoated 14 hi 26 gh
One coat PUR 19 g 31 fg
Two coats PUR 12 hi 26 gh
Biodegradation
in soil
Round-2 Materials
6 months = 1 season
1.5 years = 2 seasons

5. OECD Terrestrial Plant Test for
Toxicity (Round-1 materials)
OECD Guidelines for the testing of chemicals. Test No. 208: Terrestrial plant test: seedling
emergence and seedling growth test. OECD Publishing, DOI: 10.1787/9789264070066-en
Seedling height Visual health
Material @ 21 days (cm) rating (0-5)
PLA-corn stover (90/10) 4.4 a 5 a
PHA Mirel P1004 4.4 a 5 a
Peat Fiber 4.4 a 5 a
PLA-DDGS (90/10) 4.3 a 5 a
Coir Fiber 4.3 a 5 a
PLA 100% 4.2 a 5 a
PHA Mirel P1003 4.2 a 5 a
Wood Fiber 4.1 a 5 a
PLA - Soy (50/50) 4 a 5 a
PUR-coated Paper fiber 4 a 5 a
PHA-DDGS (90/10) P1004 3.8 a 5 a
PHA-DDGS (90/10) P1003 3.7 a 5 a
PHA Mirel P1008 (10%
Starch) 3.6 a 5 a
Polypropylene 3.5 a 5 a
Paper Fiber 3.5 a 5 a
Control (no material added) 3.4 a 5 a
Tomato seedlings.
No toxicity detected
even at 10 times the
required concentration
(10,000 ppm).

6. Biodegradation
in Compost

7. Experimental Design

8. Experimental Design
• 6 replications
• 12-week compost cycle
• Turned every 2 weeks

9. Compost Trial with
Round-2 Materials
Best microbe activity between 32° and 60° C (red lines)
Mean core temperatures

10. Compost Trial with
Round-2 Materials
• 6 replications
• 12-week compost cycle
• Turned every 2 weeks
Schrader et al. 2015. Bioplastics and biocomposites for sustainable
horticulture containers: performance and biodegradation in home
compost. Proceedings GreenSys2015. Acta Hort. (In press).

11. Compost Trial with
Round-2 Materials
See videos of the trial online: www.youtube.com/channel/UCoPRMsDRlyzT7gvSJDWFrhA
Example of 100% biodegradation
PLA + Soy (50/50) after 6 weeks in compost

12. Compost Trial with
Round-3 Materials
Commercial-grade
Biocontainers

13. Compost Trial with
Round-3 Materials
Effects of Colorant
on Compostability
99% Renewable
Material
100% Renewable
Material
PLA-BioRes™ (80/20)

14. Compost Trial with
Round-3 Materials
Commercial-grade
Biocontainers
Container material
Percentage
degradation (%)
Number of bins
at 100%
degradation
PHA-DDGS (80/20) 100 a 6
PLA-Soy (60/40) 100 a 6
PLA-Soy-BioRes (50/30/20) 100 a 6
PLA-Soy-BioRes (55/35/10) 100 a 6
PLA-BioRes (80/20) 96 a 5
PLA-BioRes (Green Colorant) 92 a 5
PLA-BioRes (Blue Colorant) 89 a 4
Recycled PLA 84 ab 3
PLA-Lignin (90/10) 70 b 3
PUR-coated Paper Fiber 28 c 0
HDPE control 0 d 0
Polypropylene control 0 d 0
• 6 replications
• 12-week compost cycle
• Turned every 2 weeks
PLA-BioRes with colorant
Green = (80/20)
Blue = (70/30)

15. Compost Trial with
Round-3 Materials
Best microbial activity between 90° and 140° F
Mean core temperatures
over 12 weeks
Temperature
(°F)
Time (Weeks)

16. Compost Trial with
Round-3 Materials
Commercial-grade
Biocontainers
Mean temperature (°F) Number of days above
Bin #
Mean
degradation (%)
Across
12 weeks
First
3 weeks Week 1 140 °F 130 °F 120 °F
2 100 103 138 154 10 13 16
4 100 101 132 150 8 10 16
3 99 102 134 150 8 10 17
5 92 101 129 148 7 8 14
6 80 103 114 127 2 6 26
1 47 102 113 127 1 5 10
Correlation coefficient (r) -0.12 0.87 0.86 0.89 0.82 0.32
Coefficient of determination (r2) 0.01 0.75 0.74 0.79 0.68 0.11
P > F 0.82 0.026 0.029 0.018 0.044 0.537
Correlation between bin temperature and degradation of the five
PLA-based materials that showed <100% degradation across bins

17. Compost Trial with
Round-3 Materials
Commercial-grade
Biocontainers
Correlation between bin temperature and degradation of the five
PLA-based materials that showed <100% degradation across bins
Degradation rate and completeness is strongly correlated with
temperature in a way that includes some or all of the following:
Correlation coefficient
Number of days above 140 °F 0.89
Temperature during the first 3 weeks 0.87
Temperature during the first week 0.86
Number of days above 130 °F 0.82

18. Material Cost $
Approximate cost of materials per pound
New Recycled
Material $/lb $/lb
Petrol-based PP 1.10 0.76
Petrol-based HDPE 1.00 0.65
SP.A (ISU High-percentage Soy polymer) 0.74
Soy protein isolate 1.14
PLA 1.10 0.60
PHA 2.00
BioRes 0.30
DDGS 0.08
Corn stover 0.03
Lignin (NeroPlast, polymer filler) 0.30
PolyAmide 3.90
Recycled paper fiber 0.36
Polyurethane (dip coat) 2.71

19. Estimated Material Cost Per Container
Round-3 Materials
New material Recycled material
cost per cost per
container (¢) container (¢)
Commercially available
petroleum-based (polypropylene)
3.9 2.7
Petroleum-based (polypropylene)
in VistaTek mold
6.5 4.5
PLA-BioRes (80/20) 8.5 4.8
PLA-Lignin (90/10) 8.9 5.0
PLA-Soy-BioRes (50/30/20) 7.7 5.4
PLA-Soy-BioRes (55/35/10) 7.9 5.4
PLA-Soy (60/40) 8.7 6.0
PLA Resin 9.5 5.2
PHA-DDGS (80/20) 12.0 NA
Our cost to purchase
Paper fiber and dip coat (¢)
Uncoated 3.0 14.0
Two coats PUR 6.0 17.0
Injection-molded
Biocontainers made
on VistaTek mold
Values shown in red
indicate estimates for
biocontainers
included in round 3.

21. On The Horizon
Pelletized Bioplastic Fertilizer
US Patent Pending 10/20/2014
Iowa State University Research Foundation (ISURF)

22. On The Horizon
Pelletized Bioplastic Fertilizer
Proof of Concept:
Marigold in 6-inch containers for 7 weeks
Equal rate of Nitrogen (1.44 g N per container)

23. Questions ?Questions ?Questions ?Questions ?