Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films

Area of Science:

• Materials Science
• Polymer Science
• Sustainable Materials

Background:

• Growing demand for eco-friendly packaging materials.
• Need for improved properties in biopolymer blends.
• Challenges in achieving good dispersion and compatibility in polymer blends.

Purpose of the Study:

• To develop environmentally friendly packaging films with high thermoplastic starch (TPS) content.
• To evaluate the effect of TPS incorporation on the properties of LDPE/LLDPE blends.
• To determine the optimal TPS content for achieving required packaging properties.

Main Methods:

• Blending of LDPE/LLDPE with varying wt% of TPS and PE-g-MA using a twin-screw extruder.
• Film preparation via a blowing process.
• Characterization using Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and mechanical testing.

Main Results:

• TPS incorporation influenced LLDPE crystallization and showed good dispersion in PE matrices.
• PE-g-MA acted as an effective compatibilizer, confirmed by FTIR.
• Mechanical properties (tensile strength, elongation-at-break) decreased with increasing TPS content but met ASTM D4635 standards at 15 wt% TPS.
• Storage modulus, loss modulus, and complex viscosity increased with TPS addition.
• Water uptake increased by 12% with 15 wt% TPS inclusion.

Conclusions:

• LDPE/LLDPE/TPS blends with PE-g-MA compatibilizer can yield environmentally friendly packaging films.
• 15 wt% TPS content provides a balance of mechanical properties suitable for packaging applications.
• The developed films exhibit enhanced water uptake, indicating potential for specific packaging uses.