Thermoreversible Networks: Viscoelastic Properties and by Klaas te Nijenhuis

By Klaas te Nijenhuis

This evaluation exhibits that the dimension of viscoelastic homes is a robust software within the learn of thermoreversible gels. even supposing many conclusions will be drawn approximately community improvement and its constitution, it's also proven that using extra concepts (e.g. small perspective S-ray and neutron scattering strategies and optical rotation) and the combo with thermodynamics and community types, widens the perception within the crosslinking technique and the gel constitution temendously. A common creation is through 8 Chapters touching on artificial polymers (PVC, PVAL, PMMA, playstation , PAN, PE, ABA blockcopolymers and LCP's) and 4 Chapters relating biopolymers (gelatin, agarose, carrageenans and gellan gum).

Show description

Read or Download Thermoreversible Networks: Viscoelastic Properties and Structure of Gels PDF

Similar polymers & textiles books

Flow Induced Alignment in Composite Materials

From the PrefaceThe objective of this ebook is to provide inside a unmarried quantity, unique info in regards to the technological know-how, processing, purposes, characterization and houses of composite fabrics bolstered with brief fibres which have been orientated in a popular path through flows bobbing up in the course of processing.

Chemicals and Materials from Renewable Resources

Content material: Chemical and fabrics from renewable assets / Joseph J. Bozell -- Polyhydroxyalkanoates: the reply to sustainable polymer construction / Tillman U. Gerngross -- imaginative and prescient for renewable assets / James S. Mclaren -- Synthesis of đ-aminolevulinic acid / Luc Moens -- Levulinate esters from biomass wastes / Edwin S.

Thermofluids

The 2 linked matters of thermodynamics and fluid mechanics are mixed during this ebook to supply the reader with an easy-to-follow textual content which emphasizes the basic coherence of the cloth.

Additional info for Thermoreversible Networks: Viscoelastic Properties and Structure of Gels

Example text

Ohta et al. [85] studied the isothermal crystallization behaviour of commercial poly(vinyl chloride) and concluded that the exponent n in the Avrami equation has values between I and 2. They explain this behaviour as heterogeneous lineal (n = 1) or homogeneous lineal (n = 2) growth of the crystals. Their main conclusions are: a) gelation is caused by crystallites; this was already proven by Alfrey et al. [64-66] and by Hendus (see [59] and [67]) with the aid of X-ray diffraction and confirmed by Dorrestijn et al.

9 Time Temperature Superposition In order to increase the frequency window of the dynamic moduli, normally use is made of the time-temperature superposition principle. However, this principle can only be applied to systems in which the structure does not depend on temperature and, consequently, not to ageing (gelating) systems. Te Nijenhuis et al. [10-12], however, were able, by making use of an extrapolation procedure, to extend the procedure to ageing systems in the following way. After having aged the system for a certain time at a fixed temperature Ta, the moduli were measured over a frequency range as large as possible.

00 10001Tm(K"~) poly(vinyl chloride) used can be calculated from Ahu as given by Anagnostopoulos et al. 75 kJ/mol, respectively. g. [71,1). Extrapolation to c = 100% yields a melting temperature of the PVC used of 223 °C. 4 Solvent Dependence A systematic study of the gelation properties of various solvents and plasticizers has been reported by Walter [110], Juijn et al. [82, 841, Teplov et al. [120,1 and Te Nijenhuis et al. [10, 11, 13, 31]. As an example, results are shown in Fig. 9 wt% solution of Solvic 239 in three different plasticizers [11,1, namely D O P , dibutyl phthatate (DBP) and Reomol ATM (the trimetlitic acid ester of alphanol 79, a mixture of branched alcohols).

Download PDF sample

Rated 4.73 of 5 – based on 46 votes