A New Method for the Preparation of Crystalline Polyvinyl Chloride

Burleigh, P. H.

doi:10.1021/ja01488a065

Cited by 65 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…26,27 However, only very small size differences between the substituents can be tolerated for an isomorphous substitution; for example, if the substituent is increased from F to Cl to yield poly(vinyl chloride), only a very small degree of crystallinity is developed, through selective crystallization of the longest syndiotactic sequences. 28,29 Second, a strong specific interaction between chains, such as hydrogen bonding, can stabilize the regular packing required for crystallization, even though the atactic nature of the polymer necessarily means that not all the repeat units can orient in such a way as to participate in this interaction. Poly(vinyl alcohol) is a classic example.…”

Section: Resultsmentioning

confidence: 99%

“…There are, of course, exceptions. First, when the substitutents on the stereogenic carbons are of similar size, m and r dyads can cocrystallize in a common lattice via an isomorphous substitution; poly(vinyl fluoride), a highly crystalline polymer which nevertheless contains both regio and stereo defects, is a classic example. , However, only very small size differences between the substituents can be tolerated for an isomorphous substitution; for example, if the substituent is increased from F to Cl to yield poly(vinyl chloride), only a very small degree of crystallinity is developed, through selective crystallization of the longest syndiotactic sequences. , Second, a strong specific interaction between chains, such as hydrogen bonding, can stabilize the regular packing required for crystallization, even though the atactic nature of the polymer necessarily means that not all the repeat units can orient in such a way as to participate in this interaction. Poly(vinyl alcohol) is a classic example. , However, hPN does not correspond to either of these cases; it is a saturated hydrocarbon polymer with only dispersive interactions between chains, and the units that are responsible for the stereoirregularity (see Figure ) are cyclopentylene rings, which can hardly be considered small.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Hydrogenated Ring-Opened Polynorbornene: A Highly Crystalline Atactic Polymer

Lee

2005

Macromolecules

159

View full text Add to dashboard Cite

Ring-opening metathesis polymerization (ROMP) of norbornene with most catalysts produces a polymer with an atactic placement of the cyclopentylene rings, yet partial hydrogenation of this polymer is known to yield a crystalline product. We report here a facile catalytic route to saturate polynorbornene (PN); fully hydrogenated polynorbornene (hPN) is highly crystalline, with an equilibrium melting point estimated as 156 °C. The crystal lattice is monoclinic, with parameters a = 6.936 Å, b = 9.596 Å, c = 12.420 Å, and β = 130.7° at room temperature, indicating nearly complete extension of the hPN backbone within the unit cell. The material remains highly crystalline until the melting point is reached, but near 105 °C, the crystal structure transforms to one characterized by substantial rotational disorder of the hPN chains about their axes, while retaining substantial translational order.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Hydrogenated Ring-Opened Polynorbornene: A Highly Crystalline Atactic Polymer

Lee

2005

Macromolecules

159

View full text Add to dashboard Cite

show abstract

“…Its [77] in THF was 1.005 dl/g a t 250C4 leading to an M , of 86,400.5 GPC indicated M , and M , of about 35,000 and 70,000.4 Infrared measurements of the ratio of absorbance at 635 cm-I to that at 692 cm-' indicated a crystallinity of about 8%. [6][7][8][9][10] Blends were made by solution casting from THF. (The resulting films were somewhat less crystalline than the films cast from methyl ethyl ketone employed by Ong.4) Dilute solutions (2% by weight) were made with continuous stirring for at least 6 hr at room temperature.…”

Section: Sample Preparationmentioning

confidence: 99%

Small‐angle x‐ray and light scattering studies of the morphology of blends of poly(ϵ‐caprolactone) with poly(vinyl chloride)

Khambatta

Warner

Russell

et al. 1976

J. Polym. Sci. Polym. Phys. Ed.

273

117

View full text Add to dashboard Cite

Solvent‐cast films of blends of poly(ϵ‐caprolactone) (PCL) with poly(vinyl chloride) (PVC) were examined by low‐angle x‐ray scattering and by small‐angle light scattering. X‐ray scattering from crystalline compositions were analyzed using the Tsvankin–Buchanan technique and led to values of the repeat period of the lamellar structure and the thickness of the crystalline and amorphous layers. With increasing content of PVC, the amorphous layer thickness increased sufficiently to accommodate the PVC, leading to values of the linear crystallinity consistent with macroscopic measurements by density and DSC techniques up to about 50% PVC by weight. Above this concentration, the lamellar structure no longer appeared to be volume filling. At high concentration of PCL, the polymer consisted of volume‐filling spherulites containing the lamellar substructure. Spherulite sizes were measured by light scattering and absolute light scattering intensities were consistent with calculations based upon the degree of crystallinity and anisotropy of the spherulites. Compositions containing more than 60% PVC were amorphous. Low‐angle x‐ray scattering was interpreted in terms of the Debye–Bueche theory which leads to values for a correlation distance lc and the mean‐square electron density fluctuation 〈η2〉 (which was also obtained from the invariant). By the method of Porod, the correlation distances were resolved into persistence lengths within the two phases, which were determined as a function of composition. The fluctuation 〈η2〉 was analyzed in terms of a two‐phase model to show that its value was somewhat larger than would be obtained if the phases were composed of the pure components. It was not possible to uniquely determine their compositions. The data were consistent with the existence of a transition zone of the order of 30 Å thick between phases.

show abstract

“…More detailed information on the characterization of this PVC series has been reported elsewhere.15,16 Butyraldehyde PVC was prepared by a free-radical polymerization in n-butyreddehyde at 50 °C. [19][20][21][22] The conversion of the reaction was approximately 13 %. The weight-averaged molar mass (M") and the polydispersity (MJMa) were 2200 g/mol and 1.4, respectively.…”

Section: Methodsmentioning

confidence: 99%