Effects of sample preparation method on mixing and phase separation in binary polymer blends

Biodegradable Hydrogenated Dimer Acid-Based Plasticizers for PLA with Excellent Plasticization, Thermal Stability and Gas Resistance

The use of vegetable oil-dervied plasticizers to enhance the flexibility of polylactic acid (PLA) has received much attention due to their renewability, inexpensiveness and biodegradation. However, the double bonds in vegetable oil-based plasticizers limit their compatibility with PLA, resulting in PLA-derived products with reduced flexibility. Herein, we examined soybean oil-derived hydrogenated dimer acid-based polyethylene glycol methyl ether esters (HDA-2n, 2n = 2, 4, 6 or 8, referring to the ethoxy units) developed via the direct esterification of saturated hydrogenated dimer acid and polyethylene glycol monomethyl ethers. The resulting HDA-2n was first used as a plasticizer for PLA, and the effects of the ethoxy units in HDA-2n on the overall performance of the plasticized PLA were systematically investigated. The results showed that, compared with PLA blended with dioctyl terephthalate (DOTP), the PLA plasticized by HDA-8 with the maximum number of ethoxy units (PLA/HDA-8) exhibited better low-temperature resistance (40.1 °C vs. 15.3 °C), thermal stability (246.8 °C vs. 327.6 °C) and gas barrier properties. Additionally, the biodegradation results showed that HDA-8 could be biodegraded by directly burying it in soil. All results suggest that HDA-8 could be used as green alternative to the traditional petroleum-based plasticizer DOTP, which is applied in the PLA industry.

Chain entanglement and molecular dynamics of solution-cast PMMA/SMA blend films affected by hydrogen bonding between casting solvents and polymer chains

The effects of intermolecular interaction between casting solvents and polymer chains on molecular entanglement and dynamics in solution-cast PMMA/SMA films were probed by rheological, dielectric and modulated DSC methods.