PBS STARCH
Additive grade
STARCH = pBS/starch blend
Lowest-cost compostable compound for shopping bags and mulch film where high bio-content and price matter more than strength.
Values for the STARCH condition
Other PBS grades and fills
PBS is listed in 4 conditions; see the grade overview at PBS.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
STARCHThis page PBS/starch blend | Lowest-cost compostable compound for shopping bags and mulch film where high bio-content and price matter more than strength. | 16 | 18 | 120 | 62 Shore D |
Mineral filled | Cost-down and stiffness-up compound for compostable trays, cutlery and thick-wall parts; sacrifices elongation and toughness. | — | 24 | 25 | — |
Poly(butylene succinate-co-adipate) copolymer | Softer, lower-melting copolymer for flexible mulch film and soil-biodegradable applications where fast degradation and high elongation are needed. | — | 25 | 700 | 50 Shore D |
toughened compostable alloy | Use when PLA rigidity/clarity is needed but PLA alone is too brittle; PBS acts as tough, flexible phase. | 40 | 42 | 90 | 72 Shore D |
What is PBS STARCH?
PBS STARCH is PBS in the STARCH grade — lowest-cost compostable compound for shopping bags and mulch film where high bio-content and price matter more than strength. PBS STARCH has a yield strength of 16 MPa (2.32 ksi) and a tensile strength of 18 MPa (2.61 ksi) — weaker than 83% of polymer grades. Elongation at break is 120% and the elastic modulus is 0.85 GPa (0.123 Msi). PBS STARCH has a density of 1.3 g/cm³ (0.047 lb/in³), heavier than 69% of polymer grades. Its glass-transition temperature is -32°C (-26 °F).
Advantages
- Low embodied carbon — 2.6 kg CO₂/kg, better than 89% of polymer grades
Limitations
- Absorbs moisture — dry before molding — 2%, worse than 97% of polymer grades
- Limited service temperature — 60°C (140 °F), worse than 87% of polymer grades
- Low strength — 16 MPa (2.32 ksi), worse than 83% of polymer grades
PBS STARCH properties
Typical room-temperature values for PBS STARCH; 26 are specific to this condition. Other listed values are PBS reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
PBS STARCH has a density of 1.3 g/cm³ (0.047 lb/in³), heavier than 69% of polymer grades. Its glass-transition temperature is -32°C (-26 °F).
Mechanical10
PBS STARCH has a yield strength of 16 MPa (2.32 ksi) and a tensile strength of 18 MPa (2.61 ksi) — weaker than 83% of polymer grades. Elongation at break is 120% and the elastic modulus is 0.85 GPa (0.123 Msi).
Thermal11
PBS STARCH is rated for continuous service to 60°C (140 °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 120 µm/m·K (66.7 µin/in·°F).
Electrical2
Chemical & Environmental2
UV resistance is poor.
Sustainability3
Producing a kilogram of PBS STARCH takes about 60 MJ of energy and emits 2.6 kg of CO₂ — less than 96% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PBS STARCH's machinability is good (55/100, worse than 64% of polymer grades); weldability very good (70/100); formability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PBS STARCH
Is PBS easy to machine?
Machinable with sharp positive-rake tools and air cooling, but low stiffness and a 115 °C melting point make it gummy — light cuts and no coolant that promotes hydrolysis.
Can PBS be welded?
Excellent heat sealing, hot-plate, hot-air and ultrasonic welding; seals at low temperature (~110–130 °C), which is why it is used as a paper-cup coating.
Can PBS be formed, bent or molded?
Dry 2–4 h at 60–80 °C (dew point ≤ -20 °C) to avoid hydrolytic MW loss; melt 160–200 °C, mold 20–40 °C; slow crystallization means longer cycles or nucleated grades, and blown film runs on LDPE-type lines.
What surface finishes work on PBS?
Prints and heat-transfer decorates well after corona treatment; avoid solvent-based paints and hot alkaline cleaning, which attack the ester backbone.
PBS 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 |
|---|---|---|
| succinic acid (succinate unit)petro- or bio-based (fermentation) succinic acid | 45 – 60 | 58 |
| adipic acidonly in PBSA copolymer grades (typ. 10–25 mol % of diacid) | 0 – 25 | 0 |
| chain extender / catalyst residue (Ti, iMW build-up additives | 0 – 1 | 0.3 |
| 1,4-butanediol (butylene unit)balance of the C8H12O4 repeat unit | ≥ 40 (balance) | — |
PBS STARCH — frequently asked
What is PBS STARCH used for?
PBS STARCH is typically used for compostable mulch film, biodegradable packaging, disposable cutlery/bags and 3D printing filament. In short: compostable PE-like polyester; low-temperature heat sealing; softer than PLA.
What is the yield strength of PBS STARCH?
PBS STARCH has a typical yield strength of 16 MPa (2.32 ksi) and a tensile strength of 18 MPa (2.61 ksi) — weaker than 83% of polymer grades. Strength varies by condition: see the 4 listed tempers.
Is PBS STARCH easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machinable with sharp positive-rake tools and air cooling, but low stiffness and a 115 °C melting point make it gummy — light cuts and no coolant that promotes hydrolysis.
Can PBS STARCH be welded?
Yes — weldability is rated very good (70/100). Excellent heat sealing, hot-plate, hot-air and ultrasonic welding; seals at low temperature (~110–130 °C), which is why it is used as a paper-cup coating.
What surface finishes work on PBS STARCH?
Prints and heat-transfer decorates well after corona treatment; avoid solvent-based paints and hot alkaline cleaning, which attack the ester backbone.
Can PBS STARCH be formed, bent or molded?
Dry 2–4 h at 60–80 °C (dew point ≤ -20 °C) to avoid hydrolytic MW loss; melt 160–200 °C, mold 20–40 °C; slow crystallization means longer cycles or nucleated grades, and blown film runs on LDPE-type lines.
What is the maximum service temperature of PBS STARCH?
PBS STARCH is rated for continuous use to about 60°C (140 °F), and briefly to 100°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- BioPBS FZ71PM / FZ91PM / FD92PM technical data — PTT MCC Biochem (2022)
- Bionolle 1000/3000 series product data — Showa Denko (Resonac) (2020)
- EN 13432 Packaging — requirements for compostability — CEN (2000)
- GB/T 19277 / GB/T 38082 — SAC (2019)
- Handbook of Biodegradable Polymers (aliphatic polyesters chapter) — Wiley/De Gruyter (2020)
- CAMPUS-format thermoplastic property records (ISO 527/178/75/306) — CWFG (2023)
- PBS/PBAT (2025)
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.