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The low‐temperature mechanical relaxation of elastin. I. The dry protein
Author(s) -
Pezzin G.,
Scandola M.,
Gotte L.
Publication year - 1976
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1976.360150206
Subject(s) - elastin , chemistry , viscoelasticity , relaxation (psychology) , activation energy , tangent , dissipation factor , thermodynamics , intensity (physics) , glass transition , analytical chemistry (journal) , materials science , chromatography , polymer , organic chemistry , physics , medicine , psychology , social psychology , geometry , mathematics , optoelectronics , pathology , dielectric , quantum mechanics
The low‐temperature relaxation of native ox Ligamentum nuchae elastin and of two purified elastin samples has been investigated in the dry state by means of the Rheovibron DDV II viscoelastometer, at the fixed frequencies of 3.5, 11, 35, and 110 Hz. Besides the glass transition at about 200°C, a relatively strong secondary loss‐tangent peak, whose activation energy is about 13 kcal/mol, is found for all samples below room temperature. The peak maximum is at −71°C for the 3.5‐Hz frequency. On the basis of its location, intensity, and width, it is attributed to a main‐chain relaxation of the pure protein. When suitable reduced variables are used, the loss‐tangent‐temperature curves obtained at different frequencies can be satisfactorily superimposed to give a master curve. Comparison of the data with the prediction of a semiempirical viscoelastic model can also be considered satisfactory.