Preparation of pure gallium

The miscibility of polylactic acid (PLA) and atactic poly(methyl methacrylate) (PMMA) blends is investigated as a function of composition. The blends quenched from the melt show the presence of a single glass transition temperature dependent on the composition. The equilibrium melting temperature is determined using the Hoffman-Weeks method and a depression is observed with increasing content of the PMMA component. The PLA spherulite growth rate and the overall isothermal crystallization rates decrease with increasing the amount of the amorphous component. The increase of the long period value as a function of the PMMA content in the blend is due to the segregation of PMMA component in the amorphous PLA interlamellar regions. The Lauritzen-Hoffman secondary nucleation theory analysis shows that the segregation of the PMMA in the interlamellar region induces an increase in the surface entropy of folding.

show abstract

“…The experimental data may be fitted by the Hoffman‐Weeks equation:

T_{m} = \frac{1}{γ} T_{c} + true(1 - \frac{1}{γ} true) T^{0}_{m}

where 1/γ, is the stability parameter, which depends on the crystal thickness.…”

Section: Resultsmentioning

confidence: 99%

Miscible blends of polylactide and poly(methyl methacrylate): Morphology, structure, and thermal behavior

Canetti

Cacciamani

Bertini

2014

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

show abstract

“…Shown in Figure 8 are the plots of T ′ m as a function of T c for pure PCL and the hybrids with various TEOS/PCL over a wide range of undercooling. The experimental data were fitted by the Hoffman‐Weeks equation34, 35: where Φ is a stability parameter, which is related to morphological factors concerning the perfection and size of crystals. In eq 5, Φ may assume values between 0 and 1.…”

Section: Resultsmentioning

confidence: 99%

Inorganic–organic hybrids involving poly(ε‐caprolactone) and silica network: Hydrogen‐bonding interactions and isothermal crystallization kinetics

Nie

Zheng

Lü

et al. 2005

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

Inorganic–organic hybrids mediated by hydrogen‐bonding interactions involving silicon oxide network and poly(ε‐caprolactone) (PCL) were prepared via an in situ sol–gel process of tetraethoxysilane in the presence of PCL. Fourier transform infrared spectroscopy indicated that there were hydrogen‐bonding interactions between carbonyls of PCL and silanol hydroxyls that were formed by incomplete polycondensation in the sol–gel process. In terms of the frequency shift of the hydroxyl stretching vibration bands, it is concluded that the strength of the interassociation between PCL and silicon oxide networks is weaker than that of the self‐association in the control silica network. The phenomenon of equilibrium melting point depression was observed for the PCL/silica system. The hybridization of PCL with silica network causes a considerable increase in the overall crystallization rate and dramatically influences the mechanism of nucleation and growth of the PCL crystallization. The analysis of isothermal crystallization kinetic data according to the Hoffman‐Lauritzen theory shows that with increasing silica content in the hybrids, the surface energy of extremity surfaces increases dramatically for the hybrids. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2594–2603, 2005

show abstract

“…5 is 1 in regimes I and III and 2 in regime II. Hoffman and Weeks [26,27] found that T ! ¼ T g -30 K and U* ¼ 1500 cal/mol by fitting the crystallization rate data for various polymers.…”

Section: Resultsmentioning

confidence: 99%

Isothermal crystallization behavior of polyamide 6,6/multiwalled carbon nanotube nanocomposites

Lin

Chen

Liu

et al. 2009

Polymer Engineering & Sci

View full text Add to dashboard Cite

The good dispersion of functionalized multiwalled carbon nanotube (f‐MWCNT) in polyamide 6,6 (PA 6,6) matrix was prepared by solution mixing techniques. The crystalline structure and crystallization behaviors of PA 6,6 and PA 6,6/f‐MWCNT nanocomposites were studied by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and polarized optical microscopy (POM) analysis. DSC isothermal results revealed that the overall isothermal crystallization rates of PA 6,6 increased as well as the activation energy of PA 6,6 extensively decreased by adding f‐MWCNT into PA 6,6, suggesting that the addition of f‐MWCNT probably induces the heterogeneous nucleation. The effect of f‐MWCNT on the chain arrangement for the crystallization of PA 6,6/f‐MWCNT nanocomposites was also discussed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

show abstract

Preparation of pure gallium

Cited by 51 publications

References 0 publications

Miscible blends of polylactide and poly(methyl methacrylate): Morphology, structure, and thermal behavior

Miscible blends of polylactide and poly(methyl methacrylate): Morphology, structure, and thermal behavior

Inorganic–organic hybrids involving poly(ε‐caprolactone) and silica network: Hydrogen‐bonding interactions and isothermal crystallization kinetics

Isothermal crystallization behavior of polyamide 6,6/multiwalled carbon nanotube nanocomposites

Contact Info

Product

Resources

About