PBSA STARCH
Additive grade
STARCH = starch-filled compostable compound
Lowest-cost compostable shopping-bag compound; sacrifices strength, elongation and moisture stability for price and bio-content.
Values for the STARCH condition
Other PBSA grades and fills
PBSA is listed in 4 conditions; see the grade overview at PBSA.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
High-melt-flow extrusion-coating / injection grade | Pick for paper-cup and paperboard extrusion coating or thin-wall injection where low melt viscosity and fast line speed are needed. | 11 | 18 | 500 | 44 Shore D |
STARCHThis page Starch-filled compostable compound | Lowest-cost compostable shopping-bag compound; sacrifices strength, elongation and moisture stability for price and bio-content. | 11 | 14 | 250 | 52 Shore D |
Mineral (CaCO₃ / talc) filled grade, 20–40 % | Choose for stiffer, cheaper sheet, tableware and thick film where nucleation and dimensional stability help offset lost ductility. | 14 | 17 | 120 | 58 Shore D |
PBSA/PLA toughened compostable compound | Use when PLA stiffness and heat resistance are required but brittleness must be removed; PBSA acts as the soft phase. | 29 | 32 | 180 | 60 Shore D |
What is PBSA STARCH?
PBSA STARCH is PBSA in the STARCH grade — lowest-cost compostable shopping-bag compound; sacrifices strength, elongation and moisture stability for price and bio-content. PBSA STARCH has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 14 MPa (2.03 ksi) — weaker than 89% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.45 GPa (0.0653 Msi). PBSA STARCH has a density of 1.31 g/cm³ (0.0473 lb/in³), heavier than 71% of polymer grades. Its glass-transition temperature is -43°C (-45 °F).
Advantages
- Low embodied carbon — 2.6 kg CO₂/kg, better than 89% of polymer grades
- Readily welded — 78/100, better than 84% of polymer grades
- Ductile — tolerates forming and impact — 250%, better than 79% of polymer grades
Limitations
- Needs corrosion protection — 32/100, worse than 99% of polymer grades
- Absorbs moisture — dry before molding — 2.5%, worse than 98% of polymer grades
- Limited service temperature — 50°C (122 °F), worse than 94% of polymer grades
- Low strength — 11 MPa (1.6 ksi), worse than 89% of polymer grades
- Difficult to machine — 30/100, worse than 87% of polymer grades
PBSA STARCH properties
Typical room-temperature values for PBSA STARCH; 28 are specific to this condition. Other listed values are PBSA reference data and may not represent this condition. Bars are the position among polymer grades.
Physical7
PBSA STARCH has a density of 1.31 g/cm³ (0.0473 lb/in³), heavier than 71% of polymer grades. Its glass-transition temperature is -43°C (-45 °F).
Mechanical12
PBSA STARCH has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 14 MPa (2.03 ksi) — weaker than 89% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.45 GPa (0.0653 Msi).
Thermal10
PBSA STARCH is rated for continuous service to 50°C (122 °F). It conducts heat at 0.24 W/m·K (0.139 BTU/hr·ft·°F), better than 67% of polymer grades. Thermal expansion is 180 µm/m·K (100 µin/in·°F).
Electrical4
PBSA STARCH is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 99% of polymer grades. UV resistance is poor.
Sustainability3
Producing a kilogram of PBSA STARCH takes about 55 MJ of energy and emits 2.6 kg of CO₂ — less than 98% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PBSA STARCH's machinability is poor (30/100, worse than 87% of polymer grades); weldability very good (78/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PBSA STARCH
Is PBSA easy to machine?
Machines poorly — very soft and rubbery; use sharp positive-rake tools, high speed, low feed and cooling air, or die-cut/laser-cut film instead.
Can PBSA be welded?
Excellent heat, impulse and ultrasonic sealing at 100–130 °C, well below other biopolymers; solvent bonding is not practical.
Can PBSA be formed, bent or molded?
Dry pellets to <0.03 % moisture, keep melt 140–185 °C to avoid hydrolytic and thermal degradation; slow crystallisation demands cool moulds, long chill rolls and anti-block for film.
What surface finishes work on PBSA?
Surface treats readily by corona for flexo printing and water-based inks; avoid hot-water or alkaline cleaning which hydrolyses the surface.
PBSA chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| butylene succinate unit (1,4-butanediol mol% of ester repeat units | 60 – 85 | 75 |
| butylene adipate unit (1,4-butanediol + adipate comonomer lowers Tm and crystallinity | 15 – 40 | 25 |
| chain extender / catalyst residues (e.g.process additive, grade dependent | 0 – 1.5 | 0.5 |
| stabilisers, anti-block, slip additivesfilm grades | 0 – 2 | 0.5 |
PBSA STARCH — frequently asked
What is PBSA STARCH used for?
PBSA STARCH is typically used for mulch film, compost bags, flexible biodegradable packaging and PLA toughening modifier. In short: softest biodegradable PBS type; lowest-temperature heat sealing; PLA impact modifier.
What is the yield strength of PBSA STARCH?
PBSA STARCH has a typical yield strength of 11 MPa (1.6 ksi) and a tensile strength of 14 MPa (2.03 ksi) — weaker than 89% of polymer grades. Strength varies by condition: see the 4 listed tempers.
Is PBSA STARCH easy to machine?
Not especially — machinability is rated poor (30/100, worse than 87% of polymer grades). Machines poorly — very soft and rubbery; use sharp positive-rake tools, high speed, low feed and cooling air, or die-cut/laser-cut film instead.
Can PBSA STARCH be welded?
Yes — weldability is rated very good (78/100). Excellent heat, impulse and ultrasonic sealing at 100–130 °C, well below other biopolymers; solvent bonding is not practical.
What surface finishes work on PBSA STARCH?
Surface treats readily by corona for flexo printing and water-based inks; avoid hot-water or alkaline cleaning which hydrolyses the surface.
Can PBSA STARCH be formed, bent or molded?
Dry pellets to <0.03 % moisture, keep melt 140–185 °C to avoid hydrolytic and thermal degradation; slow crystallisation demands cool moulds, long chill rolls and anti-block for film.
What is the maximum service temperature of PBSA STARCH?
PBSA STARCH is rated for continuous use to about 50°C (122 °F), and briefly to 70°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- BioPBS FD92PM / FD92PB technical data — PTT MCC Biochem / Mitsubishi Chemical (2023)
- Bionolle #3000 series (PBSA) product data — Showa Denko / Resonac (2021)
- Handbook of Biodegradable Polymers — poly(butylene succinate) copolyesters — Wiley (2020)
- EN 13432 Packaging — requirements for compostability — CEN (2000)
- PBS/PBSA/PBAT (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.