The structure of amorphous polystyrene by X-ray scattering and simple conformational analysis

Adams, Rachel M; Balyuzi, H. H. M.; Burge, R. E.

doi:10.1007/bf00647784

Cited by 27 publications

(16 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Poliuretanski materijali uglavnom pokazuju amorfna svojstva [31]. Hasala i saradnici [32] utvrdili su da kod amorfnog polimera sa neuređenom strukturom, difrakcioni dijagrami naročito zavise od veza konstantne dužine i uglova u ponavljajućoj jedinici polimernog lanca [33]. Difraktogram takvih materijala je jedinstven zahvaljujući njihovoj konfiguraciji i konformaciji.…”

Section: Stepen Kristalnosti Sintetisanih Poliuretanskih Materijalaunclassified

The influence of hard segment content on mechanical and thermal properties of polycarbonate-based polyurethane materials

Pavličević

Špírková

Budìnski‐Simendìć

et al. 2012

Hem Ind

View full text Add to dashboard Cite

Aliphatic segmented polyurethanes were prepared by one-step procedure in catalytic reaction between polycarbonate diol, hexamethylene-diisocyanate and 1,4-butandiol (as chain extender). The hard segment content TS was varied (17, 24, 30 and 42 wt. %) by changing the ratio of starting compounds. The soft segment is made from flexible aliphatic polycarbonate diol, while hard segments consist of chain extender and diisocyanate component. In order to study the hydrogen bonding formation and phase separation, Fourier transform infrared spectroscopy (FT-IR) was used. Wide angle X-ray scattering (WAXS) was performed to determine a degree of crystallinity and to investigate the phase behavior of prepared elastomers. The effect of TS content on mechanical properties (tensile strength, elongation at break and hardness) was tested. Thermal behavior of prepared novel polycarbonate-based polyurethanes was investigated using differential scanning callorimetry (DSC). It was determined that the elastomer which contains the highest amount of urethane groups in its structure (TS content of 42 wt. %) exhibits the most pronounced phase separation and the highest degree of crystallinity. All prepared polyurethanes exhibit high elongation at break (over 700%). The glass transition temperature Tg of prepared samples was in the temperature region from −39 to −36°C, and it was found to be slightly influenced by the soft segment content. The enthalpy of chain segments relaxation in diffused region between hard and soft domains (detected in the temperature range from 35 to 55 °C) was decreased with the increase of hard segment content. The multiple melting of hard segments (connected with the dissruption of physical crosslinks) appeared above 100 °C. It was found that the melting enthalpy linearly increases with the increase of urethane group content. Sample with 42 wt. % of TS has the highest value of melting enthalpy (41.5 J/g)

show abstract

Section: Stepen Kristalnosti Sintetisanih Poliuretanskih Materijalaunclassified

The influence of hard segment content on mechanical and thermal properties of polycarbonate-based polyurethane materials

Pavličević

Špírková

Budìnski‐Simendìć

et al. 2012

Hem Ind

View full text Add to dashboard Cite

show abstract

“…In previous analyses of the scattering from isotropic polymer samples [18,4,5] it has been tacitly assumed that the experimental scattering may be adequately described by the average scattering from a single chain segment for s values greater than 1.5 A -1. This lower limit of the s range over which the experimental scattering may be considered to be devoid of the effects of interchain correlation must remain a matter for careful consideration for each material system evaluated.…”

Section: Scattering From Uniaxial Systemsmentioning

confidence: 99%

Conformational analysis of oriented non-crystalline polymers using wide angle X-ray scattering

Mitchell

Windle

1982

Colloid & Polymer Sci

View full text Add to dashboard Cite

A procedure is presented for obtaining conformational parameters from oriented but non-crystalline polymers. This is achieved by comparison of the experimental wide angle X-ray scattering with that calculated from models but in such a way that foreknowledge of the orientation distribution function is not required. X-ray scattering intensity values for glassy isotactic poly(methylmethacrylate) are analysed by these techniques. The method could be usefully applied to other oriented molecular systems such as liquid crystalline materials.

show abstract

“…This analysis is facilitated by comparison of the experimental scattering with that calculated from models (Wright, 1974;Adams, Balyuzi & Burge, 1976;Lovell, Mitchell & Windle, 1980). For practical as well as structural reasons the size of these models is limited and consequently the calculated scattering contains an unwanted small-angle component, which is only de-0567-7394/81/040488-03501.00 pendent upon the shape and size of the model.…”

mentioning

confidence: 99%

“…The simplest method of reducing the effect of the small-angle scattering is to increase the size of the model (Adams, Balyuzi & Burge, 1976) and so move the influence of the scattering to even smaller angles. This is only really effective if it is possible to increase the dimensions of the model in all directions.…”

mentioning

confidence: 99%

“…For models which may be assumed to have one of these smooth envelopes, the small-angle scattering may be readily calculated and subtracted from the total scattering (Wright, 1974), although the 'surface roughness' of a small model may introduce significant aberrations. Adams, Balyuzi & Burge (1976) and Lovell, Mitchell & Windle (1980) have compared the experimental scattering from non-crystalline polymers with that calculated for a single isolated polymer chain. This type of model is generally neither spherical nor cylindrical.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Eliminating the small-angle component of the scattering calculated for models

Mitchell¹

1981

Acta Cryst Sect A

View full text Add to dashboard Cite

show abstract

The structure of amorphous polystyrene by X-ray scattering and simple conformational analysis

Cited by 27 publications

References 20 publications

The influence of hard segment content on mechanical and thermal properties of polycarbonate-based polyurethane materials

The influence of hard segment content on mechanical and thermal properties of polycarbonate-based polyurethane materials

Conformational analysis of oriented non-crystalline polymers using wide angle X-ray scattering

Eliminating the small-angle component of the scattering calculated for models

Contact Info

Product

Resources

About