ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Here, as part of our experimental investigations dealing with poly(urethane-isocyanurate)networks, we investigate model irregular networks with increasing amount of dangling chains. Inour study such an irregular network topology was obtained by partial substitution of a diol for amonohydroxy component during the preparation of isocyanate terminated precursors. Telechelicdiisocyanates were synthesized from aromatic diisocyanate (2,4-TDI), α,ω-dihidroxypoly(oxypropylene) (PPG 2000), and diethyleneglycolmonomethylether (an aliphatic low-molecularweightmonool component). The networks in undiluted state were prepared by cyclotrimerisation, inthe presence of a catalyst. The network properties were estimated by multiple extraction in solvent,differential scanning calorimetry and photoelastical measurements. Independently of mechanicaltesting, the fraction and concentration of dangling and elastically active network chains wereevaluated by the theory of branching processes (cascade theory). The influence of dangling chainson the mechanical properties was analyzed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.518.399.pdf
