Green pathways for nonisocyanate
polyurethane (NIPU) production
have attracted increasing levels of interest. The reaction between
5-membered cyclic carbonate and polyamines is one of the most promising
pathways to produce NIPU polymers. Though promising, major technical
hurdles such as slow polymerization rate and poor performance hinder
the commercialization of NIPU. In this paper, we screened several
commercially available triglyceride oil feedstocks for NIPU products,
focusing on polymerization kinetics and product performance for industrial
application. The impact of carbonated group density on polymerization
rate and mechanical strength was determined. We have demonstrated
a remarkably higher reactivity of carbonated oil derived from feedstocks
with polyunsaturated fatty acid (PUFA). The NIPU derived from such
feedstocks also showed improved performance for industrial application.
Unlike traditional polyurethane foam production that uses isocyanate
and water to generate CO2 as a blowing reagent, there is
no gas formation in NIPU polymerization. We have demonstrated a practical
and cost-effective approach to produce NIPU foam material using bicarbonate
as a blowing reagent. Furthermore, we conducted the first-ever technoeconomic
analysis (TEA), revealing that profitable commercial NIPU production
can be achieved when operating at sufficient production capacities.
An evolving understanding of elastomeric polymer nanocomposites continues to expand commercial, defense, and industrial products and applications. This work explores the thermomechanical properties of elastomeric nanocomposites prepared from bisphenol A diglycidyl ether and three amine-terminated poly(propylene oxides) (Jeffamines). The Jeffamines investigated include difunctional crosslinkers with molecular weights of 2000 and 4000 g mol and a trifunctional crosslinker with a molecular weight of 3000 g mol . Additionally, carbon nanotubes (CNTs) are added, up to 1.25 wt%, to each thermoset. The findings indicate that the T and storage modulus of the polymer nanocomposites can be controlled independently within narrow concentration windows, and that effects observed following CNT incorporation are dependent on the crosslinker molecular weight. Finally, the impact of crosslinker length and architecture as well as CNT addition on the molecular weight between crosslink points in the glassy and rubbery states are discussed.
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