DSC characterization of enzymatic digestion of corneas treated with plant extracts rich in polyphenols

Bersanetti, Patrícia Alessandra; Cruz, Luiz Guilherme Ito da; Carlstron, Regina; Schor, Paulo; Morandim-Giannetti, Andreia de Araújo

doi:10.1007/s10973-019-08534-9

Cited by 5 publications

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The possible explanation for the abovementioned behavior is that strong intermolecular interactions form, and molecular chain movement is restricted when MgCl 2 is added; as a result, no significant variation in crystal enthalpy is observed. 25 The results agree with the NMR and FTIR spectra, implying that the cross-linking reaction occurs when MgCl 2 is added to EVOH.…”

Section: Thermal Behavior Of Evoh and Evoh/mgcl 2 Blendssupporting

confidence: 82%

Effects of cross-linking by MgCl₂ as an initiator on the properties of EVOH

Wang

et al. 2020

Journal of Thermoplastic Composite Materials

View full text Add to dashboard Cite

Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through 13C nuclear magnetic resonance spectroscopy (13C NMR) and Fourier-transform infrared (FTIR) spectrometry. In 13C NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of –C=C– was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of –OH to form –C=C–, and –C=C– was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.

show abstract

Section: Thermal Behavior Of Evoh and Evoh/mgcl 2 Blendssupporting

confidence: 82%