PHBH
Grade
also Biopol
PHBH = poly
Choose the HHx copolymer for straws, films and cutlery coatings needing 80% elongation and the best seawater degradation; stiffness drops to 0.8 GPa and service temperature to 75 °C.
Values for the PHBH condition
Other PHB grades and fills
PHB is listed in 6 conditions; see the grade overview at PHB.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Poly | Use the adjustable-4HB copolymer where flexibility dominates — up to 200% elongation at 0.5 GPa — for films, straws and resorbable medical parts, accepting rigid-to-elastomeric low stiffness. | 14 | 20 | 200 | 50 Shore D |
Plasticized / impact-modified PHB compound | Pick the citrate/ATBC-plasticized or rubber/PBAT-toughened compound for production films and molded parts: 40% elongation and usable impact traded against 1.2 GPa stiffness and 70 °C service. | 18 | 20 | 40 | 62 Shore D |
PHBHThis page Poly | Choose the HHx copolymer for straws, films and cutlery coatings needing 80% elongation and the best seawater degradation; stiffness drops to 0.8 GPa and service temperature to 75 °C. | — | 22 | 80 | 60 Shore D |
Natural-fiber / wood-flour filled PHB | Choose the 20–30% wood-flour, bamboo or wheat-straw filled fully bio-based compound for disposable containers and garden parts, accepting 2% elongation, higher brittleness and water uptake. | 28 | 28 | 2 | 78 Shore D |
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), 3–12 mol% HV | Pick the 3–12 mol% HV copolymer for cutlery, packaging and molded parts: HV units lower melting point and crystallinity, widening the processing window and raising elongation to 12% at 30 MPa. | — | 30 | 12 | — |
Nucleated / talc-filled PHB | Specify the 1–15% talc or boron-nitride nucleated grade for thin-wall molded tableware: shorter cycles, no secondary-crystallization embrittlement, highest stiffness at 4.2 GPa but only 3% elongation. | 32 | 32 | 3 | 80 Shore D |
What is PHBH?
PHBH is PHB in the PHBH grade — choose the HHx copolymer for straws, films and cutlery coatings needing 80% elongation and the best seawater degradation; stiffness drops to 0.8 GPa and service temperature to 75 °C. PHBH has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 22 MPa (3.19 ksi) — weaker than 66% of polymer grades. Elongation at break is 80% and the elastic modulus is 0.8 GPa (0.116 Msi). PHBH has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 57% of polymer grades. Its glass-transition temperature is -1°C (30 °F).
Advantages
- Low embodied carbon — 2.2 kg CO₂/kg, better than 93% of polymer grades
PHBH properties
Typical room-temperature values for PHBH; 12 are specific to this condition. Other listed values are PHB reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PHBH has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 57% of polymer grades. Its glass-transition temperature is -1°C (30 °F).
Mechanical11
PHBH has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 22 MPa (3.19 ksi) — weaker than 66% of polymer grades. Elongation at break is 80% and the elastic modulus is 0.8 GPa (0.116 Msi).
Thermal11
PHBH is rated for continuous service to 75°C (167 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).
Electrical4
PHBH is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental2
UV resistance is fair.
Sustainability3
Producing a kilogram of PHBH takes about 60 MJ of energy and emits 2.2 kg of CO₂ — less than 96% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PHBH's machinability is good (55/100, worse than 64% of polymer grades); weldability fair (50/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PHBH
Is PHB easy to machine?
Turns, mills and drills, but the material is brittle and a poor conductor of heat. Use sharp tools, high speed, light feed and ample cooling to avoid stress cracking and edge chipping.
Can PHB be welded?
Hot-plate, ultrasonic and hot-air welding all work, but temperature must be held close to 175 °C. Overheating causes immediate thermal degradation with yellowing and odour.
Can PHB be formed, bent or molded?
Dry before injection moulding or extrusion (80 °C for 2-4 h, moisture below 0.05 %) and hold melt strictly at 165-180 °C with the shortest possible residence time. High crystallinity causes marked post-moulding shrinkage, so use a nucleating agent and 50-60 °C tools; thermoforming and blown film normally need copolymer or plasticised grades.
What surface finishes work on PHB?
Printable and labellable, and takes water-based or UV coatings, preferably after corona treatment. Not suitable for high-temperature bake finishes or solvent cleaning, since chlorinated solvents dissolve it.
PHB 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 |
|---|---|---|
| residual biomass / ashfermentation extraction residue; lower for medical grade | 0 – 1.5 | 0.5 |
| 3-hydroxybutyrate (3HB)homopolymer; partly replaced by 3HV/3HHx/4HB in copolymers | ≥ 97 (balance) | — |
PHBH — frequently asked
What is PHBH used for?
PHBH is typically used for rigid biodegradable packaging, PHA blend base resin, agricultural film additive and medical microcapsules. In short: stiffest PHA grade; highest-temperature PHA; brittle base blending resin.
What is the yield strength of PHBH?
PHBH has a typical yield strength of 35 MPa (5.08 ksi) and a tensile strength of 22 MPa (3.19 ksi) — weaker than 66% of polymer grades. Strength varies by condition: see the 6 listed tempers.
Is PHBH easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Turns, mills and drills, but the material is brittle and a poor conductor of heat. Use sharp tools, high speed, light feed and ample cooling to avoid stress cracking and edge chipping.
Can PHBH be welded?
With care — weldability is rated fair (50/100). Hot-plate, ultrasonic and hot-air welding all work, but temperature must be held close to 175 °C. Overheating causes immediate thermal degradation with yellowing and odour.
What surface finishes work on PHBH?
Printable and labellable, and takes water-based or UV coatings, preferably after corona treatment. Not suitable for high-temperature bake finishes or solvent cleaning, since chlorinated solvents dissolve it.
Can PHBH be formed, bent or molded?
Dry before injection moulding or extrusion (80 °C for 2-4 h, moisture below 0.05 %) and hold melt strictly at 165-180 °C with the shortest possible residence time. High crystallinity causes marked post-moulding shrinkage, so use a nucleating agent and 50-60 °C tools; thermoforming and blown film normally need copolymer or plasticised grades.
What is the maximum service temperature of PHBH?
PHBH is rated for continuous use to about 75°C (167 °F), and briefly to 140°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Handbook of Biodegradable Polymers — polyhydroxyalkanoates chapter — De Gruyter / Rapra (2020)
- ENMAT Y1000 series PHBV resin data — TianAn Biopolymer (2023)
- Green Planet PHBH resin technical data — Kaneka (2023)
- CAMPUS / UL Prospector — CAMPUS (2024)
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.