Biodegradable Material Choice Dilemma

        The global bioplastics market has reached $18 billion by 2024, but consumers are often confused when facing the three mainstream materials: PLA, PBAT and PHA. According to the latest research conducted by the International Sustainable Materials Association (ISMA):

73% of consumers are unable to differentiate between these three materials

65% of “eco-friendly” products have exaggerated promotions

Only 12% of users understand the degradation conditions required for different materials

Part I: Comparison of Basic Characteristics

1.1 Raw Materials and Production Process

Characteristics PLA PBAT PHA

Raw Material Sources Corn/Sugarcane Starch Petroleum + Biobased Blend Microbial Fermentation

Production Process Starch Fermentation – Polymerization Chemical Synthesis Bacterial Culture – Extraction

Energy Consumption Medium (30MJ/kg) Higher (45MJ/kg) Low (22MJ/kg)

Water Consumption 5m³/kg 8m³/kg 2m³ /kg

Data source: 2024 Life Cycle Assessment (LCA) report

1.2 Physical property performance

Laboratory measured data (25℃ standard environment):

Tensile strength: PLA(60MPa) > PHA(45MPa) > PBAT(25MPa)

Elongation at break: PBAT(600%) > PHA(300%) > PLA(5%)

Heat resistance temperature: PHA(120℃) > PBAT(80℃) > PLA(60℃)

Part II: The Ultimate PK of Environmental Performance

2.1 Comparison of Degradability

Degradation rates in different environments (6 months):

Environment PLA PBAT PHA

Industrial composting 90% 95% 98%

Home composting 15% 60% 85%

Seawater <5% 30% 92%

Soil 10% 70% 95%

NOTE: Data from the International Degradation Testing Consortium Report 2024

2.2 Carbon Footprint Analysis

Full cycle carbon emissions from feedstock to Full cycle carbon emissions from degradation (kg CO₂e/kg material):

PLA: 2.1 (mainly from crop cultivation)

PBAT: 3.8 (petroleum-based feedstock contributes 65%)

PHA: 1.2 (some strains can be carbon negative)

2.3 Risk of microplastics

Accelerated ageing experiments show:

PLA: 0.5-2 μm microplastic particles produced

PBAT: 1-5 μm particles produced

PHA: virtually no production (complete bioassimilation)

Part III: Recommended Application Scenarios

3.1 Best Choices for Food Packaging

Requirements Recommended Materials Rationale

Cold Drinks Cups/Salad Boxes PLA Highly Transparent, Low Cost

Hot Drinks Cup Lids PHA High Temperature Resistant to 120℃

Flexible Packaging Film PBAT Blend Flexible, Heat Sealable

3.2 Guidelines for Daily Use Purchase

Shopping Bags: PBAT + PLA (7:3) Blend (Balance Strength & Degradability)

Straws: Pure PHA (Bite & Chew Resistant, Ocean Biodegradable) Straws: pure PHA (resistant to biting and chewing, marine degradation)

Tableware: PLA+mineral filler (improves heat resistance)

3.3 Recommendations for Agriculture

Mulch: PBAT (cost-effective, degradation starts in 3 months)

Seedling pots: PHA (direct burial for planting, degradation in 60 days)

Part IV: Market Status to 2024

4.1 Price Trends ($/kg)

Material 2023 2024 2025 Forecast

PLA 2.3 2.1 1.8

PBAT 3.5 3.0 2.6

PHA 5.0 4.2 3.5

4.2 Policy Support

EU: PHA products are entitled to a 15% green subsidy

China: PBAT films are included in the subsidy for the purchase of agricultural machinery

US: PLA food packaging FDA approval accelerated

Part V: Consumer’s Guide to Avoiding Pitfalls

5.1 Certification Marks Interpretation

✅ True Environmental Certification:

OK Compost INDUSTRIAL (industrial composting)

OK Compost HOME (home composting)

TÜV Marine Degradable (marine degradation)

❌ False Advertisement Keywords:

“Degradable” (no specific criteria)

“Oxygen Degradable”

“Partially Bio-based”

5.2 Simple testing method

Three steps for home verification:

Burning test: real PLA has a sweet smell, PHA has no black smoke

Hot water test: PLA will soften at 60°C

Degradation observation: PHA fragments should decompose significantly in a warm and humid environment for 2 weeks