PDLLA
PDLLA is the amorphous racemic poly(DL-lactide) member of the bio-based PLA family, with low crystallinity and faster hydrolytic degradation than PLLA.
Reference datasheet — PDLLA is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PDLLA grades and fills
PDLLA is supplied in 6 conditions, soft to hard.
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 |
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 |
Supply forms, finishes and certifications
Ways PDLLA is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
NATDefault | Unfilled / Natural | Standard supply |
What is PDLLA?
PDLLA is the amorphous racemic poly(DL-lactide) member of the bio-based PLA family, with low crystallinity and faster hydrolytic degradation than PLLA. Engineers specify it where a clear, resorbable matrix with predictable erosion is needed; it is supplied as pellets, powder and solution-grade resin in low- and high-molecular-weight, acid-terminated, 70/30 L/DL, PEG-block and plasticised conditions. Strength is moderate (50 MPa tensile, 5 % elongation, 3.0 GPa modulus) and the roughly 55 °C Tg limits service to about 45 °C, with no steam sterilisation possible. Use PLLA where strength must be retained for months. PDLLA has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is 55°C (131 °F). PDLLA has a yield strength of 48 MPa (6.96 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 53% of polymer grades. Elongation at break is 5% and the elastic modulus is 3 GPa (0.435 Msi).
What is PDLLA used for?
- drug delivery microspheres
- resorbable surgical implants
- tissue engineering scaffolds
- medical coatings
Advantages
- Low embodied carbon — 2.2 kg CO₂/kg, better than 93% of polymer grades
- Low, predictable mold shrinkage — 0.3%, better than 90% of polymer grades
- Polishes to a fine finish — 70/100, better than 77% of polymer grades
Limitations
- Needs corrosion protection — 30/100, worse than 100% of polymer grades
- Limited service temperature — 45°C (113 °F), worse than 98% of polymer grades
- Poor heat conductor — 0.15 W/m·K (0.0867 BTU/hr·ft·°F), worse than 80% of polymer grades
PDLLA properties
Typical room-temperature values; bars are the position among polymer grades.
Physical6
PDLLA has a density of 1.25 g/cm³ (0.0452 lb/in³), heavier than 64% of polymer grades. Its glass-transition temperature is 55°C (131 °F).
Mechanical14
PDLLA has a yield strength of 48 MPa (6.96 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 53% of polymer grades. Elongation at break is 5% and the elastic modulus is 3 GPa (0.435 Msi).
Thermal11
PDLLA is rated for continuous service to 45°C (113 °F). It conducts heat at 0.15 W/m·K (0.0867 BTU/hr·ft·°F), worse than 80% of polymer grades. Thermal expansion is 85 µm/m·K (47.2 µin/in·°F).
Electrical5
PDLLA is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (30/100), worse than 100% of polymer grades. UV resistance is fair.
Sustainability3
Producing a kilogram of PDLLA 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's machinability is good (60/100, better than 51% of polymer grades); weldability good (55/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PDLLA is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PDLLA
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.
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) |
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.
How much does PDLLA cost?
PDLLA is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PDLLA — frequently asked
What is PDLLA used for?
PDLLA 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?
PDLLA has a typical yield strength of 48 MPa (6.96 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 53% of polymer grades. Strength varies by condition: see the 6 listed tempers.
Is PDLLA easy to machine?
Reasonably — machinability is rated good (60/100, better than 51% 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 be welded?
Yes — weldability is rated good (55/100). 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?
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 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?
PDLLA is rated for continuous use to about 45°C (113 °F), and briefly to 60°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PDLLA cost?
PDLLA is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.