Thermoplastic Polyurethane Elastomer Molecular Weight-Property Relations. Further Studies

Poly(ester urethane)s with polycaprolactone soft segments: A morphological study

“…Polycaprolactone (PCL)‐based materials, including polyurethanes, were extensively investigated in the early 1970s by the groups of Cooper,8–10 Schollenberger,11–13 and Koleske,14–16 who focused on the structure–property relationships. The biodegradability of polyurethanes has been well documented,17–22 and that of PCLs has been reported to depend on the molecular weight,23–25 but a conclusive correlation between the morphology (crystallinity, in this case), molecular weight, and biodegradation properties has not been established yet.…”

Tailor-made thermoplastic elastomers: customisable materials via modulation of molecular weight distributions

“…A reduction in internal chain-chain friction corresponds to a reduction in hysteresis energy. 35,38,39 Expectantly, polymers with MWDs tailing towards low molar mass have the lowest values of hysteresis energy, since lower MW chains can be pulled away from PS domains more easily than higher MW chains. Using this internal friction based argument, the overall reduction in hysteresis energy for polymers with increased Đ PS relative to the reference polymer is then unsurprising, as polydisperse systems have already been shown to possess decreased internal friction relative to monodisperse systems.…”

Chemistry of Non-Solvent Containing Polyurethan e cOating Systems

“…Comparing polymers 2 to 1 and 3, it is seen that this system has a higher modulus and hardness. This is attributable to the structure regularity of this polymer, (2) relative to (1) and (3). The tetra-methylene radical, (CH 2 )4 is common to the glycol moiety in the polyester and the chain extender.…”

“…The first part will deal with uses; the second part will deal with a survey of structure and properties [1,2] . Experimental work done in the Millmaster Onyx laboratory has also been included in the survey.…”

“…These data indicate the effect of the symmetrical structure of pphenylene-diisocyanate on the final physical properties of polymer one compared to the other systems. That this molecule is rigid and compact is reflected in the Shore &dquo;A&dquo; hardness and 300% modulus of polymer (1) compared to polymers (2) and (3).…”