scholarly journals Thermoplastic polyurethanes with controlled morphology based on methylenediphenyldiisocyanate/isosorbide/butanediol hard segments

2015 ◽  
Vol 64 (11) ◽  
pp. 1607-1616 ◽  
Author(s):  
Ivan Javni ◽  
Olivera Bilić ◽  
Nikola Bilić ◽  
Zoran S Petrović ◽  
Eric A Eastwood ◽  
...  
Keyword(s):  
Thermoplastic Polyurethanes ◽  
Controlled Morphology ◽  
Hard Segments

The effect of separation of blocks on the crystallization kinetics and phase composition of poly(butylene adipate) in multi-block thermoplastic polyurethanes

2022 ◽  
Author(s):  
Marina A. Gorbunova ◽  
Evgenii V. Komov ◽  
Leonid Yu. Grunin ◽  
Mariya S. Ivanova ◽  
Ainur F. Abukaev ◽  
...  
Keyword(s):  
Phase Composition ◽  
Phase Separation ◽  
Crystallization Kinetics ◽  
Separation Process ◽  
Degree Of Crystallinity ◽  
Thermoplastic Polyurethanes ◽  
Phase Separation Process ◽  
Hard Segments ◽  
Final Degree

Control of the phase separation process of soft and hard segments by selecting diisocyanates and by varying the thermal program allows defining the final degree of crystallinity and phase composition of TPUs.

Influence of hard segments content on thermal, morphological and mechanical properties of homo and co-polyurethanes: a comparative study

2021 ◽  
Vol 1 (109) ◽  
pp. 5-16
Author(s):  
Z.K. Alobad ◽  
M. Albozahid ◽  
H.Z. Naji ◽  
H.S. Alraheem ◽  
A. Saiani
Keyword(s):  
Mechanical Properties ◽  
Ethylene Glycol ◽  
Exothermic Peak ◽  
Thermoplastic Polyurethanes ◽  
Main Challenge ◽  
New Type ◽  
Hard Segments ◽  
Poly Ethylene ◽  
Poly Propylene ◽  
Hydrogen Bonded

Purpose: This work aims to study the effect of hard segments (HS) content on the thermal, morphological and mechanical properties of polyurethane polymers based on 1.5 pentanediol chain extenders. Design/methodology/approach: Two comparable series of polyurethanes were synthesised including homo-polyurethane (Homo-PU) and copolyurethane (Co-PU). The Homo-PU consists of 100% wt. of hard segments (HS). The Co-PU composes of 30%wt. of soft segments (SS) using a poly(ethylene glycol)-block-poly(propylene glycol)-blockpoly( ethylene glycol) material. The effect of hard segments content on the morphology of Homo-PU and Co-PU was also studied. Findings: The Homo-PU and Co-PU materials show three distinct degradation steps with the higher thermal stability of the Co-PU compared to the Homo-PU. Enthalpy of fusion (ΔHM) and heat capacity (ΔCP) of polyurethane (PU) samples decrease with decreasing HS content. In the cooling cycle, the higher exothermic peak of crystallization is observed in the Co-PU. In contrast, the cold crystalline peak is observed in the 2nd heating cycle of the Homo-PU. Melting temperature (TM) increases with increasing SS content. Glass transition temperature (Tg) of PU samples shifts to higher temperature with increasing HS content. Storage modulus (E’) of the Co-PU is higher than E’ of the Homo-PU. All N-H groups in PU samples are hydrogen-bonded, whilst most of the C=O groups are hydrogen-bonded. The degree of hydrogen bonding in PU samples decreases with decreasing HS content. The Homo-PU shows better hardness than the Co-PU and higher brittleness at low temperature. WAXS results of the Homo-PU display better crystallinity compared to the Co-PU. Research limitations/implications: The main challenge in this work was how to synthesis Thermoplastic polyurethanes (TPUs) with specific properties to compete other common polymer such as Polyamides (PA) and Polypropylene (PP).Practical implications: Thermoplastic polyurethanes (TPUs) can be used in various application such as backageing, foot,automobiles and constructions. Originality/value: A new type of TPUs that synthesized using different type of chain extender (1.5 pentanediol). Two different types of TPUs were synthesized one contained 30% SS and 70% HS and a second one contained 100% HS.

scholarly journals A structural reconsideration: Linear aliphatic or alicyclic hard segments for biodegradable thermoplastic polyurethanes?

2018 ◽  
Vol 56 (19) ◽  
pp. 2214-2224 ◽  
Author(s):  
Konstanze Seidler ◽  
Katharina Ehrmann ◽  
Patrick Steinbauer ◽  
Andreas Rohatschek ◽  
Orestis G. Andriotis ◽  
...  
Keyword(s):  
Thermoplastic Polyurethanes ◽  
Hard Segments

Postmortem and in situ TEM methods to study the mechanism of failure in controlled-morphology high-impact polystrene resin

1996 ◽  
Vol 54 ◽  
pp. 178-179
Author(s):  
R. C. Cieslinski ◽  
M. T. Dineen ◽  
J. L. Hahnfeld
Keyword(s):  
Poisson Ratio ◽  
Acrylonitrile Butadiene Styrene ◽  
High Impact ◽  
In Situ Tem ◽  
Styrene Copolymers ◽  
Controlled Morphology ◽  
Point Bend ◽  
Mechanism Of Failure ◽  
Impact Energies

Advanced Styrenic resins are being developed throughout the industry to bridge the properties gap between traditional HIPS (High Impact Polystyrene) and ABS (Acrylonitrile-Butadiene-Styrene copolymers) resins. These new resins have an unprecedented balance of high gloss and high impact energies. Dow Chemical's contribution to this area is based on a unique combination of rubber morphologies including labyrinth, onion skin, and core-shell rubber particles. This new resin, referred as a controlled morphology resin (CMR), was investigated to determine the toughening mechanism of this unique rubber morphology. This poster will summarize the initial studies of these resins using the double-notch four-point bend test of Su and Yee, tensile stage electron microscopy, and Poisson Ratio analysis of the fracture mechanism.

ALUMINA MATRIX WITH CONTROLLED MORPHOLOGY FOR COLORED SPECTRALLY SELECTIVE COATINGS

2017 ◽  
Vol 16 (3) ◽  
pp. 715-724 ◽  
Author(s):  
Luminita Isac ◽  
Lavinia Nicoara ◽  
Ramona Panait ◽  
Alexandru Enesca ◽  
Dana Perniu ◽  
...  
Keyword(s):  
Alumina Matrix ◽  
Spectrally Selective ◽  
Controlled Morphology
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