Properties and Phase Structure of Polycaprolactone-Based Segmented Polyurethanes with Varying Hard and Soft Segments: Effects of Processing Conditions

2017 ◽  
Vol 219 (2) ◽  
pp. 1700214 ◽  
Author(s):  
Balazs Imre ◽  
Hubert Gojzewski ◽  
Casey Check ◽  
Richard Chartoff ◽  
G. Julius Vancso
Keyword(s):  
Phase Structure ◽  
Processing Conditions ◽  
Soft Segments ◽  
Segmented Polyurethanes

Phase structure in segmented polyurethanes having fatty acid-based soft segments

Polymer ◽  
2013 ◽  
Vol 54 (1) ◽  
pp. 372-380 ◽  
Author(s):  
Zoran S. Petrović ◽  
DooPyo Hong ◽  
Ivan Javni ◽  
Natalia Erina ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Phase Structure ◽  
Soft Segments ◽  
Segmented Polyurethanes

Diacetylene Containing Polyesters and Segmented Polyurethanes with Body Temperature Sensitive Thermochromic Transitions

1993 ◽  
Vol 328 ◽  
Author(s):  
Ken D. Zemach ◽  
M. F. Rubner
Keyword(s):  
Body Temperature ◽  
Soft Segment ◽  
Polymerization Process ◽  
Temperature Sensitive ◽  
Processing Conditions ◽  
Highly Sensitive ◽  
Wide Range ◽  
Soft Segments ◽  
Hard Segments ◽  
Segmented Polyurethanes

ABSTRACTSeveral diacetylene containing polyesters with thermochromic transitions at or around room temperature have been synthesized. Some of these polymers have been shown to be highly sensitive to body temperature, giving rise to either reversible or irreversible thermochromic changes, depending upon both the molecular structure and the processing conditions. By changing the structure and processing conditions, the thermochromic transition can be moved over a wide range of temperatures. Segmented polyurethanes using these diacetylene functionalized polyesters as soft segments and containing diacetylene groups in the hard segments have also been produced. Through a selective polymerization process, it is possible to selectively cross-polymerize the hard segment diacetylene groups or cross-polymerize both the hard and soft segments thereby making it possible to examine the effects of hard and soft segment crosslinking on mechanical properties.

Study on the Influences of Domain Structure of Hydrophilic Polyurethane with Partially Crystalline on its Moisture Permeability

2011 ◽  
Vol 233-235 ◽  
pp. 281-287
Author(s):  
Heng Quan ◽  
Zhen Ya Gu
Keyword(s):  
Chemical Structure ◽  
Hard Segment ◽  
Microphase Separation ◽  
Soft Segment ◽  
Moisture Permeability ◽  
Soft Segments ◽  
Separation Degree ◽  
Polyethylene Glycol 1000 ◽  
Segmented Polyurethanes ◽  
Hydrophilic Polyurethane

Multiphase, segmented polyurethanes with mixed soft segment phase were prepared from 4,4’- diphenylmethane diisocyanate (Pure MDI), polybutylene adipate (glycol) 2000 (PBA2000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Further more, the relationships between domain separation structure, crystallizability of soft segment and moisture permeability, hydrophilic property, phase inversion temperature (PIT) of the polyurethanes were investigated. The studies show that the chemical structure, concentration of hydrophilic soft monomers and the microphase separation degree of the mixed soft segments from hard segment domain have remarkable effects on the application properties of polyurethane.

Study of the Effect of Soft-Segment Length and Concentration on Properties of Polyetherurethanes. II. The Effect on Mechanical Properties

1985 ◽  
Vol 58 (4) ◽  
pp. 701-712 ◽  
Author(s):  
Zoran S. Petrović ◽  
Jaroslava Budinski-Simendić
Keyword(s):  
Mechanical Properties ◽  
Chain Length ◽  
Plastic Flow ◽  
Soft Segment ◽  
Maximum Strength ◽  
Segment Length ◽  
Elongation At Break ◽  
Mechanical Methods ◽  
Soft Segments ◽  
Segmented Polyurethanes

Abstract Three series of segmented polyurethanes with different soft segment lengths and concentrations were examined by TMA, DMA, and mechanical methods. Maximum tensile strengths were obtained when ssc was 40–50%, which was explained by a specific interlocking morphology. No significant effect of soft-segment chain length on maximum strength was found, but higher values were found in the C series when ssc was 60%. Elongation at break increases linearly with ssc but indications that shorter soft segments produce higher extensions was attributed to plastic flow. TMA showed that Tg was independent of ssc in the C and, to a degree, in the B series, while temperature of α-transition in DMA was independent of ssc only in the C series at ssc above 50%.

Polydimethylsiloxane-Based Polyurethanes: Phase-Separated Morphology and In Vitro Oxidative Biostability

2009 ◽  
Vol 62 (8) ◽  
pp. 794 ◽  
Author(s):  
Taeyi Choi ◽  
Jadwiga Weksler ◽  
Ajay Padsalgikar ◽  
Rebeca Hernéndez ◽  
James Runt
Keyword(s):  
Segmented Polyurethane ◽  
Two Phase ◽  
Dimethyl Siloxane ◽  
X Ray Scattering ◽  
Soft Segments ◽  
Hard Segments ◽  
Segmented Polyurethanes ◽  
Methylenediphenyl Diisocyanate ◽  
End Group

Three series of segmented polyurethane block copolymers were synthesized using 4,4′-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) or 1,3-bis(4-hydroxybutyl)tetramethyl disiloxane (BHTD) as the hard segments, and soft segments composed of poly(dimethyl siloxane) (PDMS)-based and poly(hexamethylene oxide) (PHMO) macrodiols. Copolymers synthesized with the PDMS macrodiol and PDMS and PHMO macrodiol mixtures consist of three microphases: a PDMS phase, hard domains, and a mixed phase of PHMO (when present), PDMS ether end-group segments and some dissolved hard segments. Degrees of phase separation were characterized using small-angle X-ray scattering by applying a pseudo two-phase model, and the morphology resulting from unlike segment demixing was found to be closely related to the in vitro oxidative biostability of these segmented polyurethanes.

Synthesis and blood compatibilities of novel segmented polyurethanes containing phosphatidylcholine analogous moieties in the main chains and long-chain alkyl groups in the side chains

1999 ◽  
Vol 14 (9) ◽  
pp. 3789-3798 ◽  
Author(s):  
Arata Korematsu ◽  
Yu-Jun Li ◽  
Takayuki Murakami ◽  
Tadao Nakaya
Keyword(s):  
Platelet Adhesion ◽  
Platelet Rich Plasma ◽  
Side Chains ◽  
Alkyl Groups ◽  
Low Degree ◽  
Soft Segments ◽  
Hard Segments ◽  
Segmented Polyurethanes ◽  
Methylenediphenyl Diisocyanate ◽  
Long Chain

New segmented polyurethanes containing phospholipid moieties in the main chains and long-chain alkyl groups in the side chains were synthesized. The soft segments used in this study were poly(butadiene), poly(isoprene), hydrogenated poly(isoprene), and poly(1,6-hexyl-1,2-ethylcarbonate) diol. The hard segments of these polyurethanes were 4,4′-methylenediphenyl diisocyanate, bis[2-(2-hydroxyethyldimethylammonio)ethyl]2-cetyl- 1,3-propanediphosphate, and 1,4-butanediol. The blood compatibilities of the new polymers were evaluated by platelet-rich plasma contact studies and viewed by scanning electron microscopy using medical grade BioSpan® and nonphospholipid polyurethane as references. These new materials have good surfaces in terms of platelet adhesion, and the morphology of adhered platelets undergoes a relatively low degree of variation.

scholarly journals Thermal and mechanical properties of linear segmented polyurethanes with butadiene soft segments

1981 ◽  
Vol 21 (11) ◽  
pp. 668-674 ◽  
Author(s):  
C. M. Brunette ◽  
S. L. Hsu ◽  
M. Rossman ◽  
W. J. MacKnight ◽  
N. S. Schneider
Keyword(s):  
Mechanical Properties ◽  
Thermal And Mechanical Properties ◽  
Soft Segments ◽  
Segmented Polyurethanes
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