Structure–property relationships of polycarbonate diol‐based polyurethanes as a function of soft segment content and molar mass

Lee

J of Applied Polymer Sci

et al. 2016

The condensation of a mixture of dimethyl carbonate and phthalate derivatives with 1,4‐butanediol (BD), catalyzed by sodium alkoxide, generated high‐molecular weight poly(1,4‐butylene carbonate‐co‐aromatic ester)s with molecular weights (Mn) of 50–120 kDa. The subsequent addition of polyols [BD, glycerol propoxylate, 1,1,1‐tris(hydroxymethyl)ethane, or pentaerythritol] chopped these high‐molecular weight polymers to afford macrodiols or macropolyols with facile control of their molecular weights (Mn, 2000–3000 Da) and unique chain topological compositions. Macropolyols prepared by chopping poly(1,4‐butylene carbonate‐co‐terephthalate) were waxy in nature, whereas those containing isophthalate and phthalate units were oily. The macropolyols synthesized by this chopping method may have potential applications in the polyurethane industry. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43754.

Section: Introductionmentioning

confidence: 99%

Chopping high‐molecular weight poly(1,4‐butylene carbonate‐co‐aromatic ester)s for macropolyol synthesis

Lee

J of Applied Polymer Sci

et al. 2016

J of Applied Polymer Sci

“…Polyurethane solutions were obtained by a standard polymerization method based on the two‐step process in dimethylacetamide; 4,4′‐diphenylmethane diisocyanate (MDI), 1,4‐butanediol (BD), and dimethyl acetamide (DMAc), as solvent, were purchased from Aldrich (Barcelona, Spain). The macrodiol Polyhexamethylene–pentamethylene carbonatediol (PH100) of molar mass 1000 g mol −1 and glass transition temperature of −51.32°C, was kindly supplied by UBE Chem Eur.…”

Section: Methodsmentioning

confidence: 99%

“…The molar ratio used for this study was PH100 : BD : MDI = 1 : 2 : 3 in mole ratio. Details on synthesis and sample preparation are given in previous articles …”

Section: Methodsmentioning

confidence: 99%

“…In contrast, polycarbonatediol (PCD) derived TPUs depict improved water and organic solvent resistance, high mechanical strength, and high heat‐resistance, at the expense of an increase in the price . In the last years, we have been working in the identification and functional characterization of improved efficiency of PCD based TPUs since few studies have been published.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal and dielectric properties of polycarbonatediol polyurethane

Ortiz-Serna

Carsí

Redondo-Foj

et al. 2015

Self Cite

Ortiz Serna, MP.; Carsí Rosique, M.; Redondo Foj, MB.; Sanchis Sánchez, MJ.; Culebras, M.; Gomez, CM.; Cantarero, A. (2015). Thermal and dielectric properties of polycarbonatediol polyurethane. Journal of Applied Polymer Science. 132 (22) ABSTRACTThe dielectric relaxation behaviour of a segmented polyurethane has been studied using Broad-Band Dielectric Spectroscopy in the frequency domain, 10 -2 -10 9 Hz, and in the temperature range of -120 to 140 ºC. The spectra show three secondary processes (,  and β) followed by the  relaxation and conductive processes. The Havriliak-Negami (HN) phenomenological equation was used in order to characterize all the processes. The ,  and  relaxations are probably associated with (i) local motions of the main chain (ii) motions of the carbonate group in the soft phase and (iii) reorientational motions of the water molecules. The microphase-separated morphology associated with soft and hard domains is reflected in the dielectric spectra, at high temperatures, by the presence of the Maxwell-Wagner-Sillars (MWS) interfacial polarization process.

Macromol. Rapid Commun.

“…Aside from the synthetic restrictions of this polymerization technique, the high elastic properties, strength, and ability to achieve a smooth shell surface make PUs good shell candidates. Also tailoring the mechanical properties with various hard and soft segments allows for unique tunability of the final product …”

Section: Polymers In Phase Change Materialsmentioning

confidence: 99%

Advanced Polymers for Reduced Energy Consumption in Architecture

Heifferon

Long

2018

In an effort to slow the progress of climate change, the current scientific community has focused on the reduction of greenhouse gases in order to limit the global average temperature inflation to less than 2 °C. The improvement of thermally controlled construction materials can potentially result in lower energy homes/reduced emissions, and lowering the thermal conductivity of insulation materials improves home energy efficiency. Nanoporous insulation foams impart a drastic decrease in thermal conductivity but many polymer properties must be assessed to produce these materials. Passive phase‐change materials also represent another key energy‐saving device to control heat flux within a living space. Research into unique polymeric systems provides a novel means of encapsulation or creating polymeric cross‐linked matrices to prevent leakage and improve mechanical robustness. These two areas of polymer research in architecture represent key advancements for construction materials aimed toward energy savings and energy‐related emissions control.