This document discusses using polyhydroxyalkanoates (PHAs) as polymeric plasticizers and process aids for PVC. PHAs were found to have similar properties to conventional ethylene copolymer resin modifiers for PVC, including lower migration rates than primary plasticizers like DINP. PHAs are also inherently miscible in PVC, making them easier to process than synthetic modifiers. Additionally, PHAs are fully bio-based and food contact approved, allowing for higher bio-content and a broader range of applications compared to conventional plasticizers.

1. PHA Modifiers as Polymeric
Plasticizers and Process Aids
Vinyltec 2014
Indianapolis
October 20-22, 2014
Allen Padwa
Sr. Science Fellow

2. © 2014 Metabolix2
Metabolix Core PHA Technology
Versatile Technology Addresses Chemicals and Polymers Markets
Manufacturing technology proven
Biopolymers: Gaining traction in the performance additives; focusing on unique
polymer properties and product forms in all biopolymer segments
Biobased Chemicals: Option to Leverage PHA platform and breakthrough “FAST”
process for chemicals
Sugars,
Natural Oils
Fermentation
Polymer
Recovery Biopolymers
Acrylic (C3),
GBL/BDO (C4)
“FAST”
Recovery
Compostables,
Degradables
Performance
Additives
Metabolix Biopolymers
Biobased Chemicals
P4HB
P3HP
PHA
Core PHA
Bioscience

3. © 2014 Metabolix3
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
Effective additive and modifier in leading polymer systems

4. © 2014 Metabolix4
Metabolix PHA Family of Copolymers
Amorphous
Range
Progress has Extended PHA Technology
into the Amorphous Region

5. © 2014 Metabolix5
Sharpen emphasis on value and performance we can
deliver to customers
Strategically selective
Established application spaces
Critical mass
Key areas of focus
PVC
PLA
Micropowders
PHA-based latex
Biopolymers Focus
Additives Approach
Additives, Modifiers

6. © 2014 Metabolix6
I6003rp/M0000 - PVC Recycle Enhancer
 Maintain properties without losing flexibility
 Lower Process Torque
 Improved homogeneity
I6002 - Toughening Flexible & Semi-rigid PVC
 Excellent miscibility process aid – Dispersion & Fusion
 Low Tg, high MW rubber property modifier – Toughness,
Elongation, Permanence, No migration
Bio-based Modifiers for PVC Take Advantage
of Inherent PHA Miscibility in PVC

7. © 2014 Metabolix7
PVC / PHA Miscibility
DMA tg δ as a function of temperature (with 18 phr DIDP):
PHA
PVC
PVC/10 phr PHA blend
61 ºC-9 ºC
53 ºC
Fox equation confirms miscibility
1
𝑇𝑔𝑏
=
𝑊1
𝑇𝑔1
+
𝑊2
𝑇𝑔2

8. © 2014 Metabolix8
PHA as Polymeric Modifier
Comparison with Plasticizers and Ethylene Copolymer Resin (ECR)
 Response factors for PVC with:
– Plasticizer (DINP or TOTM)
– a-PHA – Bio-based high MW polymeric modifier
– ECR – Conventional high MW synthetic polymeric modifier
 Basic Flexible PVC Formulation:
– CPM vs. a-PHA modifier
– Bio-based plasticizer/stabilizer - ESO
– Conventional plasticizers - DINP or TOTM
 Processing on two-roll mill at 180ºC
 Response variables: Torque, Shore D hardness, Extractability
 Analyzed by JMP (from SAS Institute)

9. © 2014 Metabolix9
Shore D Response
PHA and ECR display similar plasticization effect; but at lower rate
than the primary plasticizers (DINP, TOTM)
Factor Slope
DINP -1.24
TOTM -1.16
a-PHA -0.75
ECR -0.72
r2 = 0.97
ECR

10. © 2014 Metabolix10
Factor slope
DINP - 0.43
TOTM - 0.42
a-PHA - 0.07 *
ECR +0.02 *
(* weak effects)
r2 = 0.87
Torque Response
Polymeric additives display no significant impact on torque
ECR

11. © 2014 Metabolix11
Migration Study
Specimens were tested for migration response
 ISO 177 migration protocol
 Sandwich construction
– PVC disk – 50 mm diameter, 3 mm thick
– LDPE disk – 60 mm diameter, 1.6 mm thick
– Wrap in aluminum foil
– 5 kg weight
– Samples run in triplicate
– Heat age in oven at 70º C
– Samples removed at 1, 5, 15 and 29 days

12. © 2014 Metabolix12
Migration Study
Modeling of data
 Loss of plasticizer is limited by diffusion
 Plots of ‘Weight Loss’ vs Time0.5 are linear
 Slope is proportional to the rate of weight loss

13. © 2014 Metabolix13
Migration Response
a-PHA and ECR display lower migration responses and potential
favorable impact on conventional plasticizers
Factor slope
DINP 1.4e-4
a-PHA 4.5e-5
ECR 4.3e-5
DINP*(a-PHA) 9.9e-7
DINP*(ECR) 1.2e-6
r2 = 0.88
Slope = % wt loss/day
ECRa-PHA

14. © 2014 Metabolix14
Migration Response
Calculated plasticizer loss in 1 year at 70º C

15. © 2014 Metabolix15
Conclusions
PHAs display similar performance to an ethylene
copolymer resin (ECR)
– lower migration response than conventional plasticizers
– favorable impact on conventional plasticizer material performance
PHA modifiers are inherently miscible in PVC
>> More easily processed and incorporated than synthetics
PHAs are 100% bio-based and food-contact approved
>> Increases bio-content, supports broad range of applications