PDLLA ACID
Grade
ACID = acid-terminated (free carboxylic end-group) grade
Pick when faster hydrolysis and higher hydrophilicity are needed for burst/short-term drug release or rapid-resorbing coatings.
Values for the ACID condition
Other PDLLA grades and fills
PDLLA is listed in 6 conditions; see the grade overview at PDLLA.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
PDLLA-PEG block copolymer | Pick for micelles, thermogels and hydrophilic nanoparticle carriers; behaves as a soft/waxy or gelling material rather than a rigid plastic. | 8 | 10 | 60 | 45 Shore D |
Plasticized / impact-modified PDLLA compound | Pick when ductile membranes, films or flexible resorbable sheets are required; plasticizer (e.g. citrate/PEG/oligolactide) trades stiffness and Tg for elongation. | 24 | 28 | 120 | 62 Shore D |
Low molecular weight drug-delivery grade | Pick for microspheres, implants and in-situ gels needing weeks-to-months release; mechanically weak, used as a matrix not a structural part. | 25 | 25 | 2.5 | 78 Shore D |
ACIDThis page Acid-terminated (free carboxylic end-group) grade | Pick when faster hydrolysis and higher hydrophilicity are needed for burst/short-term drug release or rapid-resorbing coatings. | 30 | 30 | 3 | 79 Shore D |
High molecular weight structural grade | Pick for interference screws, anchors and plates needing maximum strength retention over the first months of resorption. | 55 | 58 | 7 | 84 Shore D |
Poly(L-lactide-co-D,L-lactide) 70:30 stereocopolymer | Pick for resorbable fixation where amorphous, crack-free implants are wanted but with higher stiffness and slower degradation than pure PDLLA. | 58 | 60 | 6 | 84 Shore D |
What is PDLLA ACID?
PDLLA ACID is PDLLA in the ACID grade — pick when faster hydrolysis and higher hydrophilicity are needed for burst/short-term drug release or rapid-resorbing coatings. PDLLA ACID has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 70% of polymer grades. Elongation at break is 3% and the elastic modulus is 2.5 GPa (0.363 Msi). PDLLA ACID has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is 47°C (117 °F).
Advantages
- Low embodied carbon — 2.2 kg CO₂/kg, better than 93% of polymer grades
- Low, predictable mold shrinkage — 0.4%, better than 82% of polymer grades
- Polishes to a fine finish — 70/100, better than 77% of polymer grades
Limitations
- Limited service temperature — 35°C (95 °F), worse than 100% of polymer grades
- Needs corrosion protection — 20/100, worse than 100% of polymer grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 87% of polymer grades
- Limited ductility — 3%, worse than 83% of polymer grades
- Poor heat conductor — 0.14 W/m·K (0.0809 BTU/hr·ft·°F), worse than 81% of polymer grades
PDLLA ACID properties
Typical room-temperature values for PDLLA ACID; 27 are specific to this condition. Other listed values are PDLLA reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PDLLA ACID has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is 47°C (117 °F).
Mechanical14
PDLLA ACID has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 70% of polymer grades. Elongation at break is 3% and the elastic modulus is 2.5 GPa (0.363 Msi).
Thermal11
PDLLA ACID is rated for continuous service to 35°C (95 °F). It conducts heat at 0.14 W/m·K (0.0809 BTU/hr·ft·°F), worse than 81% of polymer grades. Thermal expansion is 85 µm/m·K (47.2 µin/in·°F).
Electrical5
PDLLA ACID is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 5×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (20/100), worse than 100% of polymer grades. UV resistance is fair.
Sustainability3
Producing a kilogram of PDLLA ACID takes about 55 MJ of energy and emits 2.2 kg of CO₂ — less than 98% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PDLLA ACID's machinability is fair (48/100, worse than 75% of polymer grades); weldability fair (40/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PDLLA ACID
Is PDLLA easy to machine?
Machinable with sharp carbide/single-flute tools at high speed and low feed with air or cryogenic cooling — no water coolant (hydrolysis) and keep the part well below the 55 °C Tg to avoid smearing.
Can PDLLA be welded?
Joined by solvent bonding (dichloromethane, chloroform, ethyl acetate) or low-temperature hot-plate/ultrasonic welding; avoid prolonged melt exposure which cuts molecular weight and degradation lifetime.
Can PDLLA be formed, bent or molded?
Dry to <250 ppm (40–45 °C vacuum, never above Tg) then injection-mold at 160–200 °C melt / 20–45 °C tool with short residence time; amorphous so parts demold clear with low, isotropic shrinkage.
What surface finishes work on PDLLA?
Vapor-polish or flame-free solvent polishing gives clarity; sterilize by ethylene oxide or e-beam/gamma at controlled dose — steam autoclaving destroys the part, and gamma reduces molecular weight.
PDLLA 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 lactide monomermedical grades typically <0.5 % | 0 – 1 | 0.3 |
| tin(II) 2-ethylhexanoate catalyst residuring-opening polymerization catalyst; limited for implant use | 0 – 0.02 | 0.01 |
| alcohol initiator / end-cap (dodecanol, controls molecular weight and degradation rate | 0 – 2 | 0.5 |
| D,L-lactide (racemic lactide) repeat uni≈50:50 D- and L-lactic acid units; atactic chain, no crystallinity | ≥ 98 (balance) | — |
PDLLA ACID — frequently asked
What is PDLLA ACID used for?
PDLLA ACID is typically used for drug delivery microspheres, resorbable surgical implants, tissue engineering scaffolds and medical coatings. In short: fastest-degrading PLA type; amorphous, clear resorbable grade; drug-release matrix polymer.
What is the yield strength of PDLLA ACID?
PDLLA ACID has a typical yield strength of 30 MPa (4.35 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 70% of polymer grades. Strength varies by condition: see the 6 listed tempers.
Is PDLLA ACID easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 75% of polymer grades). Machinable with sharp carbide/single-flute tools at high speed and low feed with air or cryogenic cooling — no water coolant (hydrolysis) and keep the part well below the 55 °C Tg to avoid smearing.
Can PDLLA ACID be welded?
With care — weldability is rated fair (40/100). Joined by solvent bonding (dichloromethane, chloroform, ethyl acetate) or low-temperature hot-plate/ultrasonic welding; avoid prolonged melt exposure which cuts molecular weight and degradation lifetime.
What surface finishes work on PDLLA ACID?
Vapor-polish or flame-free solvent polishing gives clarity; sterilize by ethylene oxide or e-beam/gamma at controlled dose — steam autoclaving destroys the part, and gamma reduces molecular weight.
Can PDLLA ACID be formed, bent or molded?
Dry to <250 ppm (40–45 °C vacuum, never above Tg) then injection-mold at 160–200 °C melt / 20–45 °C tool with short residence time; amorphous so parts demold clear with low, isotropic shrinkage.
What is the maximum service temperature of PDLLA ACID?
PDLLA ACID is rated for continuous use to about 35°C (95 °F), and briefly to 60°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM F1925 — Standard Specification for Semi-Crystalline Poly(lactide) Polymer and Copolymer Resins for Surgical Implants — ASTM International (2022)
- ASTM F1635 — In Vitro Degradation Testing of Hydrolytically Degradable Polymer Resins and Fabricated Forms — ASTM International (2021)
- RESOMER R-series (poly(D,L-lactide)) product information — Evonik Health Care (2023)
- PURASORB PDL / PLDL bioresorbable polymer datasheets — Corbion (Purac Biomaterials) (2023)
- Handbook of Biodegradable Polymers / Poly(lactic acid): Synthesis, Structures, Properties, Processing and Applications — Wiley (2010)
- Bio-based thermoplastics property tables (PLA/PDLLA) — CAMPUS / producer compilations (2023)
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.