Biorenewable blends of polyamide‐11 and polylactide

Abstract

Polyamide‐11(PA11) is melt blended with polylactide (PLA) using 0.00 to 0.10 wt% titanium isopropoxide catalyst to investigate potential compatibilizing reactions. Blend properties are characterized by differential scanning calorimetry (DSC), thermogravimetric analysis, dynamic mechanical thermal analysis, and tensile and impact testing. DSC shows two separate glass transition temperatures indicating only partial miscibility. Base etching to remove PLA domains followed by field emission scanning electron microscopy confirms the two phase nature of the blends. Storage and tensile moduli of the blends increase monotonically with increasing PLA content. Interchange reactions during reactive mixing were investigated by 13C‐NMR spectroscopy but the analysis shows little evidence of interchange reactions. This is true irrespective of catalyst level and mixing time over the temperature range from 185°C to 225°C. At the upper end of the temperature range investigated, significant degradation is observed. The combined results indicate that degradation reactions dominate over compatibilizing interchain transreactions. POLYM. ENG. SCI., 54:1523–1532, 2014. © 2013 Society of Plastics Engineers

Biosourced blends based on poly (lactic acid) and polyamide 11: Structure–properties relationships and enhancement of film blowing processability

“…[5][6][7] Among these modifications, polymer blending is considered an effective and economical way to generate new materials with a wide range of properties. [16][17][18][19] These two polymers, as is often the case, are thermodynamically immiscible because of their typically low mixing entropy. [11][12][13][14][15] Polyamide 11 (PA11) or nylon 11 is a biosourced polymer derived from castor oil with a high mechanical performance.…”

Toughening of poly(lactic acid) without sacrificing stiffness and strength by melt-blending with polyamide 11 and selective localization of halloysite nanotubes

“…However, an improvement of the ductility and toughness is observed only for high PA11 contents (>50 wt%), both Young modulus and stress at break showing a substantial decrease. Recent literature reports suggest that, nanostructured polymer blends having a minor polymer phase with nanoscale dimensions offer much promise because of enhanced toughness in comparison to conventional polymer blends [10][11][12]. This method was used by Nuzzo and coworkers [13][14][15] to prepare PLA/PA11 blends containing small amounts of nanoparticles (organo-modified montmorillonite (OMMT), sepiolite and carbon nanotubes).…”

Toughening of poly(lactic acid) without sacrificing stiffness and strength by melt-blending with polyamide 11 and selective localization of halloysite nanotubes

“…The transversal images ( Figure 1a) show a "sea-island" morphology of the blends, where the continuous phase is PLA and the spherical dispersed phase represents PA11. In the longitudinal direction (Figure 1a'), heterogeneous discontinuous fibrillar morphology is observed which is attributed to the viscosity difference between the PLA and PA11 [5]. Whatever the observation direction, the interface between PA11 and PLA seems to be weak, a clear gap between the PLA matrix and the PA11 domains being clearly observed.…”

“…Thus, numerous approaches have been adopted to correct this drawback, one of them based on melt blending PLA with a more ductile engineered polymer [2][3] such polyamide. For last case, blends with fine dispersion of the minor phase, strong interfacial adhesion, compatibilization effects and, in some case a slight improvement of the ductility can be obtained [4][5]. Nevertheless but these improvements are achieved to the detriment of the rigidity and yield stress.…”