High‐performance bio‐based poly(lactic acid)/natural rubber/epoxidized natural rubber blends: effect of epoxidized natural rubber on microstructure, toughness and static and dynamic mechanical properties

• Published in: Polymer international Vol. 68; no. 3; pp. 439 - 446
• Main Authors: Nematollahi, Mahsa, Jalali‐Arani, Azam, Modarress, Hamid
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-03-2019; Wiley Subscription Services, Inc
• Subjects: compatibility; Differential scanning calorimetry; Droplets; Dynamic mechanical analysis; Dynamic mechanical properties; Elongation; Fourier transforms; Gloves; Impact resistance; Impact strength; Infrared analysis; Infrared spectroscopy; Mechanical properties; Modulus of elasticity; Morphology; Natural rubber; Organic chemistry; poly(lactic acid); Polylactic acid; Polymer blends; Rheological properties; Rubber; Scanning electron microscopy; Spectrum analysis; Tensile properties; toughness
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.5727

Attempts have been made to prepare high‐performance bio‐based blends through blending of poly(lactic acid) (PLA) with natural rubber (NR) in the presence of epoxidized natural rubber (ENR) as a compatibilizer. The prepared samples were characterized using differential scanning calorimetry, measuring the tensile properties and impact resistance, scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy and dynamic mechanical analysis (DMTA). Morphological studies revealed a matrix‐dispersed morphology for all blends, in which the average droplet size significantly decreased with the use of ENR. The elongation at break and impact strength of the blend containing 3 wt% ENR were 45 and 16 times those of neat PLA, respectively. These values are significantly higher than those previously reported for various simple and dynamically vulcanized rubber‐toughened PLAs. The influence of ENR on compatibility was confirmed by rheological tests, FTIR spectra and DMTA. DMTA also showed a marked increase in elastic modulus for the blend in the presence of 3 wt% ENR. The tensile properties and impact resistance were directly dependent on the ENR content and rubber droplet size. © 2018 Society of Chemical Industry
ENR improved the interfacial adhesion between PLA and NR and decreased the droplet size, whereby the impact strength of the blend containing 3 wt% ENR was 16 times that of neat PLA.