The Relations between Polymer Structure and Properties in Urethans

1960 ◽  
Vol 33 (5) ◽  
pp. 1259-1292 ◽  
Author(s):  
J. H. Saunders

Abstract Sufficient data are available from studies of urethan foams and elastomers to draw semiquantitative conclusions regarding the effect of any gross structural change on most polymer properties. These relationships apply to other areas of application as well, e.g., coatings, adhesives and sealants. Future research may be expected to provide more reliable control of the many reactions involved in preparing urethans, thus better control over structure. Similarly a more quantitative and extensive knowledge of polymer properties may be expected. The result of these combined efforts will be a more precise knowledge of structure-property relationships and an improved ability to produce polymers having the properties desired for a wide range of applications.

1962 ◽  
Vol 35 (4) ◽  
pp. 970-1012 ◽  
Author(s):  
Takehide Tanaka ◽  
Tetsuo Yokoyama

Abstract The field of polyurethans is rapidly growing in commercial importance, especially in form and elastomer applications. This group of polymers includes a very broad region of chemical structures and chain length. In many cases polyurethans are synthesized from polyester glycols or polyether glycols and diisocyanates so that the urethan groups are even fewer in number than other functional groups. This process of synthesis enables us to deal with a very wide range of polymer properties, adding interest to the studies of relation between structure and properties. Though a considerable number of publications dealing primarily with the properties of urethan polymers have been published, few of them contribute to better understanding of the relation between these properties and the corresponding polymer structure. Within the last few years information of value has become available, and Saunders has established some semi-quantitative relations by the use of such data. He also discusses in his reports general considerations concerning structure-property relationships. Although his considerations and conclusions show a marked progress, they are not theoretically satisfactory yet, especially from a quantitative viewpoint. The authors have investigated structure-property relationships in polyurethans for a few years and written some papers concerning synthesis, reaction kinetics, some physical properties, network structure, and dynamic behavior of polyurethans.


1981 ◽  
Vol 54 (1) ◽  
pp. 170-180 ◽  
Author(s):  
D. M. Chang

Abstract The effect of polymer structures on the rubber processing and physical properties of the improved Hycar 1090 low compression set nitrile rubbers was investigated. The molecular weight and acrylonitrile content of a polymer are important variables in determining the compound processing and vulcanizate physical properties. Within the range of 21 to 88 Mooney, a blend of high and low Mooney polymers has approximately the same properties as those from a single polymer of the same Mooney viscosity. The molecular weight distribution was not significantly broadened to become an important factor affecting the polymer properties. All polymers with Mooney viscosities from 21 to 88 showed good properties. An understanding of the structure and properties of this new type of NBR, will help in choosing the right kind of polymer for particular applications.


RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 96611-96622 ◽  
Author(s):  
Masayuki Nagasawa ◽  
Tatsuya Ishii ◽  
Daisuke Abe ◽  
Yuji Sasanuma

The structure and properties of aromatic polyamides and polythioamides were investigated and compared with those of analogous polyesters, polythioesters, and polydithioesters.


2003 ◽  
Vol 766 ◽  
Author(s):  
Do Y. Yoon ◽  
Hyun Wook Ro ◽  
Eun Su Park ◽  
Jin-Kyu Lee ◽  
Hie-Joon Kim ◽  
...  

AbstractPolysilsesquioxanes (PSSQs) with the empirical formula (RSiO3/2)n have become very important as low-dielectric insulators for copper interconnects in the next-generation logic devices, but the detailed structure-property relationships were completely lacking. We have investigated the microstructure and functional properties of PSSQs with varying alkyl substituents and also PSSQ copolymers. As a result, significant advances have been made in the scientific understanding of PSSQ structures and significant improvements of key properties such as the crack resistance, mechanical modulus and hardness, and incorporation of nanometer-sized (<4 nm) porosity for ultra-low dielectric constants (<2.0).


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniela Tabuani ◽  
Walter Granelli ◽  
Giovanni Camino ◽  
Michael Claes

AbstractIn the field of polymer nanocomposite materials, carbon nanotubes have attracted lots of research interests in the recent past for their potentialities in improving a wide range of polymer properties. We present here a comprehensive study on polypropylene/carbon nanotube composites evaluating the morphology as well as the thermal behaviour of the prepared systems. Pristine as well as -COOH functionalised carbon nanotubes were taken into account and melt mixed at different weight fractions with PP; the crystallisation characteristics of the material were evaluated by means of DSC and XRD and the thermal behaviour was assessed through TGA analyses. The nanotubes appear to affect significantly the properties of the matrix in a way notably dependent on the functionalization and on the filler amount.


1993 ◽  
Vol 5 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Martin Davies ◽  
John N Hay ◽  
Barry Woodfine

Polyetherimides have been synthesized by two complementary routes starting from 4-halophthalic anhydride. A range of polymers has been prepared by varying the structure of the diamines and bisphenols employed in the syntheses. These polymers have been characterized by their m spectra, molecular weight and thermal properties. The applicability and limitations of the synthetic routes are discussed. Structure-property (glass transition temperature, Tg relationships are elucidated and discused in terms of the structural fragments in the polymer chain. Chain flexibility, rotational freedom and inter-chain interactions are all important parameters affecting the polymer properties. The effect of polymer molecular weight on Tg is also discussed.


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