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Modifying PLA with New Mirel™ PHA Copolymers
Bob Engle 3rd PLA World Congress Munich May 27, 2014
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© 2014 Metabolix 2
Agenda
New Metabolix PHA copolymer technology developments
Using PHA copolymers to modify PLA
– Fibers
– Sheet extrusion
– Films
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© 2014 Metabolix 3
Metabolix PHA Biopolymer Portfolio Key Features
~100% Bio-based – Made from renewable raw materials – Can use
industrial sugars and non-food plant oils
Copolyester polymer – Wide range of MW (200,000 - 700,000) –
Semi-crystalline to amorphous (Tg: - 30 to +5ºC, Tm: 120 to
180ºC)
FDA food contact: FCN1119 for PHA copolymers – Single use
(conditions B through H) – In preparation for new copolymers (FDA,
EFSA)
Biodegrade in most environments having microbial activity – Hot
to cold aerobic conditions: composting, soil, marine – Meso &
thermophilic anaerobic conditions: high & low solids
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© 2014 Metabolix 4
Metabolix PHA Family of Copolymers
Amorphous Range
Metabolix has Extended PHA Technology into the Amorphous
Region
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© 2014 Metabolix 5
Launching Products & Expanding Capacity
Metabolix is prototyping PHA products in a range of applications
including – PHA polymeric additives for PLA modification – PHA
polymeric additives for PVC modification – Aqueous dispersion (PHA
Latex) for paper coating – Marine degradable PHA Powder for
cosmetics & personal care
Expanding capacity – 2.5 - 5 kT expected on stream in 2015
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© 2014 Metabolix 6
Modifying PLA for Ductility & Toughening Approaches
Plasticizers – Modest toughening – Potential for drawbacks from
migration (physical aging) &
potential for lowering Tg (processing window)
Mineral Fillers & Reinforcements – Good toughening –
Drawbacks with ductility
“Rubber” Modifiers – Effective for both ductility and
toughness
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© 2014 Metabolix 7
Metabolix PHA Rubber Modifiers Enable Scalable Ductility in
PLA
A range of ductility improvement is possible Without lowering
the Tg of the PLA (not a miscible plasticizer)
LDPE
PLA, Paper
HDPE Blister, Cards Cups, Lids
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© 2014 Metabolix 8
Modifying PLA for Fiber Applications Improved touch &
feel
Improved touch & feel in textiles & nonwovens e.g.,
personal & home care (hygiene, medical, cleaning)
– Melt Spun & Drawn (monofilament) 5% PHA modification
Improved tenacity Improved drape and hand Reduced boiling water
shrinkage after heat set
– Melt Blown 5% PHA modification Improved softness Reduced hot
water shrinkage
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© 2014 Metabolix 9
PHA Modifiers Bring Significant Softness to PLA Fibers at Low
Loading Level
8
20
Improvements in PLA Fiber “Hand” Touch and Feel
PLA
PHA Modified
Hand, g-f (5% PHA)
60% reduction in “hand,” gives a soft, silky feel Ductility
& elongation leads to finer filaments & improved drape
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© 2014 Metabolix 10
0% 5% 10% PHA Modifier
Sheet thickness ~ 15 mil (0.37 mm) Dart 1.5” hemisphere, 752 gm,
26” height
– Dart impact strength increase – Reduced brittleness – Improved
ductility & elongation
0
10
20
30
40
50
0 5 10 15
Dart
impa
ct (g
/mil)
% PHA Modifier
Dart Impact at different PHA %
Toughening PLA Sheet: Dart impact improves with PHA modifier
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© 2014 Metabolix 11
2x, with 5% PHA modifier 2x
8x 2x
8x, with 5% PHA modifier
Rounded edges with reduced stress fracture & propagation
Crack propagation ahead of the cutting edge
Risk of fragments & splinters
Improving PLA Sheet trimming: Reduced brittle edge fracture
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© 2014 Metabolix 12
Refractive Indices
Polymer nD25
PLA 1.48 – 1.49 a-PHA 1.48 – 1.49
Complementary refractive indices
Small rubber domain sizes are important
25µ film PLA/a-PHA
Transparency Retention
0
5
10
15
20
25
0 5 10 15
Haze
(%
)
% Copolymer
PLA Clarity
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© 2014 Metabolix 13
PHA Modifiers are Immiscible in PLA
AFM of PLA / PHA blend
Two phase system (two Tg transitions)
Compatibility: for blending dispersion & domain size
Efficiency: linked to small domains & rubber properties
DSC Heating Scan @ 40 °C/minPost Cooling From the Melt @ 10
°C/min
Temperature (°C)-40 -20 0 20 40 60 80
Heat
Flo
w [E
ndo −>
]
PLA: Tg ~ 50 °CM4300: Tg ~ -35 °Ca-PHA
1 µm Small % Plasticizer included
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© 2014 Metabolix 14
a-PHA modified PLA film
Units LDPE* (typical)
PLA/ a-PHA
HDPE** (typical)
Melt index g/10 min 216 kg @ 190ºC
1.8 1.5 2.0
MD Tear g/mil 288 140 24
Dart impact g/mil 72 300 100
Tensile Strength MPa 27 40 51
Flex. Modulus MPa 500 750 1250
* Data of BFI345 1.25mil LDPE from Blue Ridge Films ** Data of
BFI6420 1.0 mil HDPE from Blue Bridge Films
Flexibility & Toughness in PLA Blown Films HDPE performance
is possible with PHA modification
Mineral filler included
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© 2014 Metabolix 15
Melt viscosity Melt elasticity Material Pa-s (50 s-1 @ 190º)
(0.25 rad/s @ 160º) PLA 1744 0.06 PLA / a-PHA 1899 0.29 LDPE 1253
0.47
Excellent Melt Strength For effective PLA film blowing
PLA draws easily but has little melt elasticity a-PHA rubber
raises the melt elasticity
Poor Bubble Stability
Limited Draw-down
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© 2014 Metabolix 16
Summary of Features Modifying PLA with Metabolix PHA
Improving PLA toughness and ductility – Softness in fibers;
single use personal care items for skin contact – Edge trimming
& toughness in sheet for blister & containers –
Flexibility, melt elasticity & tear strength in blown film
Extending the performance range to expand the market opportunity
for PLA
Maintaining the high bio-based content & compostability
PHA supplied as masterbatch for effective letdown in PLA
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Modifying PLA with New Mirel™ PHA Copolymers
Bob Engle 3rd PLA World Congress Munich May 27, 2014
Modifying PLA �with New Mirel™ �PHA CopolymersAgendaMetabolix
PHA Biopolymer Portfolio�Key FeaturesSlide Number 4Slide Number
5Modifying PLA for Ductility & Toughening �ApproachesSlide
Number 7Modifying PLA for Fiber Applications�Improved touch &
feelPHA Modifiers Bring Significant Softness to PLA Fibers at Low
Loading LevelToughening PLA Sheet:�Dart impact improves with PHA
modifierImproving PLA Sheet trimming:�Reduced brittle edge
fractureSlide Number 12Slide Number 13Slide Number 14Excellent Melt
Strength�For effective PLA film blowingSummary of
Features�Modifying PLA with Metabolix PHAModifying PLA �with New
Mirel™ �PHA Copolymers
