The effect of heat treatment on water sorption in polylactide and polylactide composites via changes in glass‐transition temperature and crystallization kinetics

Du, An; Koo, Donghun; Ziegler, Mary; Cairncross, Richard A.

doi:10.1002/polb.22258

Cited by 15 publications

(13 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Intercalation also led to a slight increase in the onset of degradation temperature. This is consistent with previous results (24)(25)(26). Surprisingly, the ammonium surfactants produced the greatest increase in thermal stability and the phosphonium surfactants did not change the degradation temperatures at all.…”

Section: Effects Of Surfactant Headgroupsupporting

confidence: 94%

Dispersion of Organically Modified Layered Silicates in Melt Blended Poly(Lactic Acid) Composites: Effects of Cation Head Groups and Oxygenated Alkyl Chains

et al. 2013

View full text Add to dashboard Cite

Extruded organically modified layered silicate (OMLS) -poly(lactic acid) (PLA) composites exhibit a mixed intercalated/exfoliated morphology.To explore effects of surfactant hydrophobicity and polarity on the quality of dispersion, a series of OMLS were prepared from quaternary ammonium, phosphonium, and imidazolium salts, including some synthesized hexadecanoic acid containing ionic liquids. The alkyl chains were modified to include aromatic and oxygen moieties while keeping the same long alkyl chain length. Nile Blue was co-exchanged to add a fluorescent tag to the layered silicates. The effectiveness of this technique for PLA and different Nile Blue salts were assessed. Degree of exfoliation was monitored using x-ray diffraction and fluorescence spectroscopy. Thermal characteristics of the new OMLS were measured.

show abstract

Section: Effects Of Surfactant Headgroupsupporting

confidence: 94%

Dispersion of Organically Modified Layered Silicates in Melt Blended Poly(Lactic Acid) Composites: Effects of Cation Head Groups and Oxygenated Alkyl Chains

et al. 2013

View full text Add to dashboard Cite

show abstract

“…If this holds true, the decrease in diffusion coefficients can just be ascribed to a more tortuous path for the diffusing molecules due to the impermeable crystals. It should be considered, however, that in our samples the mobility of the amorphous fraction could be reduced by the effect of the annealing at high temperature, as revealed by the increase of Tg [13]. It is worth noting that the diffusivity in the amorphous sample 2002D_A is about two times higher than the diffusivity in the semi crystalline samples.…”

Section: D_cs 2002d_cmmentioning

confidence: 90%

A spectroscopic approach to assess transport properties of water vapor in PLA

2015

View full text Add to dashboard Cite

“…The lower value is in the range of the estimated experimental equilibrium water uptake at room temperature. Based on the extrapolation of experimental water sorption data at 308 K [36] to a water activity of 1.0, and assuming that sorption takes place only in the amorphous domains, a maximum value of 1.3 wt%e1.4 wt% can be expected in accordance to experimental results for a completely amorphous sample [37]. For quantification of the shape-memory properties, a simulated cyclic thermomechanical test consisting of two subsequent cycles with uniaxial deformations of 100% was applied for the dry and the two moist packing models.…”

Section: Introductionmentioning

confidence: 99%

Influence of the addition of water to amorphous switching domains on the simulated shape-memory properties of poly(l-lactide)

Ghobadi

Heuchel

Kratz

et al. 2013

Polymer

View full text Add to dashboard Cite

a b s t r a c tIt is well known that the environmental conditions e.g. humidity can alter the shape-memory properties of polymers. In this work we applied an atomistic molecular dynamics simulation approach to model the influence of the addition of 1 wt% and 2 wt% water on the simulated shape-memory behavior of the amorphous switching domains of poly(L-lactide) (PLLA) with a molecular weight of M n ¼ 52,000 g mol À1 .For the dry as well as the water swollen PLLA-models, two subsequent uniaxial thermomechanical test cycles have been calculated, whereby the applied uniaxial deformation ε m was varied between 50% and 150%.All simulated PLLA models showed high shape fixity ratio of R f ! 84%. The shape-memory properties obtained at ε m ¼ 100% for the dry PLLA and the models containing 1 wt% water were almost identical with a shape recovery ratio in the first and second test cycle around R r ¼ 61%e64%. In contrast PLLA with 2 wt% water exhibited higher values of R r ¼ 76% during the first test cycle, but a lower R r ¼ 52% in the subsequent second cycle. Furthermore, increasing the applied ε m resulted in a decrease of R r from 82% to 42% for the dry PLLA, whereas PLLA with 2 wt% water did not show a dependence of R r on ε m . We anticipate that these observations can be attributed to differences in the initial structure of the various simulated PLLA models e.g. the different distribution of the free volume elements.

show abstract

The effect of heat treatment on water sorption in polylactide and polylactide composites via changes in glass‐transition temperature and crystallization kinetics

Cited by 15 publications

References 32 publications

Dispersion of Organically Modified Layered Silicates in Melt Blended Poly(Lactic Acid) Composites: Effects of Cation Head Groups and Oxygenated Alkyl Chains

Dispersion of Organically Modified Layered Silicates in Melt Blended Poly(Lactic Acid) Composites: Effects of Cation Head Groups and Oxygenated Alkyl Chains

A spectroscopic approach to assess transport properties of water vapor in PLA

Influence of the addition of water to amorphous switching domains on the simulated shape-memory properties of poly(l-lactide)

Contact Info

Product

Resources

About