Polyvinyl chloride. Part I. effect of polymerization temperature on association, second virial coefficient, and molecular dimensions

Daniels, Charles A.; Collins, E. A.

doi:10.1080/00222347408260831

Cited by 28 publications

(6 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our laboratory Bonnemayre has confirmed those results and shown that a latex particle shrinks when losing HCl but that the outer diameter is more preserved when the beam current is lower and the time of irradiation longer for a constant total irradiation. PVC-S is known for its pericellular membrane, Filisko (36) shöwed that its IR s~ectrtim was not the simple combination of the spectra of PVC and of poly(vinylalcohol) which substantiated the hypothesis of a chemical association. Pluricellular PVC partielas or monocellular ones are composed of cells which are originally spherical but much deflated in the end-product.…”

Section: Powder Resin Morphologymentioning

confidence: 80%

“…We exclude here aggregates containing suspending agents from PVC-S ( 35). Systematic studies (3,4,34,36) have shown that high molecular weight, syndiotacticity, higher concentration, separately or together, favor Unauthenticated Download Date | 5/13/18 1:41 AM aggregation ; precipi tation from dilute solutions makes subsequent .solubilization more difficult. Abdel-Alim (33) observed that two types of aggregates could exist in THF solution : strong ones, soluble at 200°C after 2 hours 0 with a 4300 A size, .made of the high molecular weight· part of LTP and weak 0 ones, soluble at 100°C with a 2500 A size composed of all types of molecular weight molecules.…”

Section: Solution Properties and Aggregatesmentioning

confidence: 99%

See 1 more Smart Citation

Characterisation of poly(vinylchloride)

Carrega¹

1977

Pure and Applied Chemistry

View full text Add to dashboard Cite

-0.5 10-3 .r;O~g branch and 5 10-3 chloromethyl group permonomer uni t (m.u.) possibly originating from head-to-head monomer placement are f.ound in industrial PVC (fewer in low-temperature polymerized products). TertiarY chlorine atoms, if any, correspond to long branches ; internal double bonds (0.05 10-3 per m.u. and over) can start polydiene sequences. 1 H and 1 3c NMR spectroscopy shows that syndiotactic placement is slightly favored over isotactic, depending only on polymerization temperature (PT). The number of aggregates in solution is very sensitive to PT,increasing with syndiotacticity, and heating up gives molecular solutions. Crystallizability increases with syndiotacticity, and two types of crystals exist ;. crystallinity is higher in virgin powder, and fusion range covers 120o to 220°C • .Annealing over 110°C develops a lower order detectable by DSC. A zone of higher density disappearing at 210°C is seen at the center of virgin PVC "one micron granules"• The temperature of pseudofusion in plasticizers depends on heat treatment, and the kinetics of impregnation reveals morphological heterogeneities.

show abstract

Section: Powder Resin Morphologymentioning

confidence: 80%

Section: Solution Properties and Aggregatesmentioning

confidence: 99%

Characterisation of poly(vinylchloride)

Carrega¹

1977

Pure and Applied Chemistry

View full text Add to dashboard Cite

show abstract

“…In the CP/MAS 13 C NMR, the naturally rare 13 C spins are polarized through the dipolar coupling with the abundant 1 H spins and the magnetization of the 1 H is transferred to the 13 C. This brings about significant enhancement of 13 C signal intensity and reduction in data acquisition time . Moreover, the MAS contributes to removal of the heteronuclear dipole−dipole interactions and the chemical shift anisotropy, thereby narrowing the line widths of the spectrum; the resonance of carbons attached to the different nuclear environments can be resolved …”

Section: Methodsmentioning

confidence: 99%

Monitoring of Homogenization and Analysis of Nanoscale Structure in a Butadiene−Acrylonitrile Copolymer/Poly(vinyl chloride) Blend

Kwak

Nakajima

1996

Macromolecules

View full text Add to dashboard Cite

The progress of homogenization in the mechanical blending of a butadiene−acrylonitrile copolymer (NBR) and a poly(vinyl chloride) (PVC) was observed with scanning and transmission electron microscopes. The significant events of the microscopic examinations were as follows: (i) NBR formed a continuous and PVC a dispersed phase. (ii) The skins of PVC grains (100−150 μm) were removed first, and the grains were broken into agglomerates (∼10 μm). (iii) The agglomerates were disintegrated stepwise into primary particles (∼1 μm), domains (∼0.1 μm), and eventually the nodular particles of the size between domains and microdomains (∼10 nm). The electron microscopic visualizations, together with the material behavior expressed in terms of the internal mixer geometry and the viscoelastic properties during mixing action, suggest a schematic model for the homogenization mechanism. The microphase structure of the finished blend was characterized by cross-polarization/magic angle spinning (CP/MAS) 13C NMR spectroscopy. Analyses of T 1 ρ spin−lattice relaxation for specific carbons permitted a precise identification of the microstructures. Double-component resolution of the magnetization decay confirmed a coexistence of a mixed phase and two microseparated phases, the latter corresponding to an unmixed NBR phase and PVC microcrystallites. From the T 1 ρ relaxation times, the sizes of the microphases were estimated to be in the nanoscale.

show abstract

“…30 wt % polymer. ,, The soft segments have the glass transition temperature of about −50 °C, and the hard segments melt at about 150 °C. ,, The number-average molecular weight is about 30 000. PVC resin was Geon 103 EP F-76 (Geon Co.) with number-average molecular weight of 40 000 and weight-average molecular weight of 89 000 …”

Section: Methodsmentioning

confidence: 99%

Morphology Formation in Mixing of Copolyester Thermoplastic Elastomer (Hytrel) with Poly(vinyl chloride) and Nuclear Magnetic Resonance Relaxation Study on Solid Structures of the Mixture

Kwak

Nakajima

1996

Macromolecules

View full text Add to dashboard Cite

A mechanical mixing of copolyester thermoplastic elastomer (Hytrel) and poly(vinyl chloride) (PVC) was carried out in an internal mixer, and the morphological changes during mixing were monitored with a scanning electron microscope. It is found that Hytrel formed a continuous phase and PVC was dispersed throughout, first by removal of skins and then gradual disintegration of the particles into the substructures of its unique hierarchy. Proton spin-lattice relaxation times in the rotating frame, T1F, were evaluated from CP/MAS 13 C NMR spectra to determine the solid morphology after the completion of mixing. Pure phases of both Hytrel and PVC microcrystallites were present, dispersed in a mixed matrix. The maximum and minimum domain sizes of the dispersed phases were estimated to be ca. 14 and 24 Å, respectively.

show abstract

Polyvinyl chloride. Part I. effect of polymerization temperature on association, second virial coefficient, and molecular dimensions

Cited by 28 publications

References 31 publications

Characterisation of poly(vinylchloride)

Characterisation of poly(vinylchloride)

Monitoring of Homogenization and Analysis of Nanoscale Structure in a Butadiene−Acrylonitrile Copolymer/Poly(vinyl chloride) Blend

Morphology Formation in Mixing of Copolyester Thermoplastic Elastomer (Hytrel) with Poly(vinyl chloride) and Nuclear Magnetic Resonance Relaxation Study on Solid Structures of the Mixture

Contact Info

Product

Resources

About