Contribution to the Study of Ethylene-Propylene Copolymers by Infrared Spectroscopy. Distribution of Monomeric Units

1965 ◽  
Vol 38 (2) ◽  
pp. 334-342 ◽  
Author(s):  
Giovanni Bucci ◽  
Tonino Simonazzi
Keyword(s):  
Infrared Spectroscopy ◽  
Numerical Evaluation ◽  
Distribution Functions ◽  
Reactivity Ratios ◽  
Block Polymers ◽  
Ethylene Propylene ◽  
Copolymer Microstructure ◽  
Catalyst Systems ◽  
Random Alternation ◽  
Theoretical Considerations

Abstract Elastomeric properties of ethylene-propylene copolymers depend not only on the composition but also on the copolymer microstructure, i.e., on the distribution of monomeric units along the macromolecular chain. According to Natta and coworkers the best polymer should be obtained when two monomeric units are randomly alternated in the macromolecule. The random alternation of the monomers is actually only partial because somewhat longer homosequences are formed. In such a case one deals with block polymers. On the basis of some theoretical considerations on the copolymerization process and also on the basis on the reactivity ratios of the two monomers, Natta and coworkers have calculated the distribution functions of sequences for various catalyst systems. Infrared spectroscopy has been widely used in connection with this problem though from different viewpoints and with different aims. The purpose of our work is to reanalyze the whole problem. We have focused our attention on the CH2 rocking band in the sequence (—CH2—)n, where n varies from 1 to 5 or more. Some disagreement exists between various authors on the assignment of these bands, especially in the case of the (—CH2—)3 and (—CH2—)4 sequences. We have then divided our work as follows: (a) assignment of infrared bands in the spectral region between 900 and 650 cm−1; (b) calculation of absorbances at various frequencies; (c) attempt at a numerical evaluation of the distribution of monomeric units.

Ethylene Propylene Copolymers. I. Monomer Reactivity Ratios

1966 ◽  
Vol 39 (2) ◽  
pp. 241-247
Author(s):  
R. D. Bushick
Keyword(s):  
Catalyst System ◽  
Reactivity Ratio ◽  
Reactivity Ratios ◽  
Feed Concentration ◽  
Monomer Reactivity Ratios ◽  
Ethylene Propylene ◽  
Random Arrangement ◽  
Catalyst Systems

Abstract Copolymerization of ethylene and propylene with diisobutylaluminum chloride and various vanadium-containing compounds gave a series of reactivity ratio values for ethyleno which decreased in the order: VO(O−n−Bu)3>VOCl(OEt)2>VOCl2OEt>VO(OEt)3≃VOCl3. All of the catalyst systems were extremely sensitive to changes in the ethylene feed concentration. The reactivity ratio product suggested a random arrangement of monomer units with each catalyst system except VOC13.

Ethylene-Propylene Copolymers Produced with Soluble Catalysts

1962 ◽  
Vol 35 (4) ◽  
pp. 1101-1113
Author(s):  
R. J. Kelly ◽  
H. K. Garner ◽  
H. E. Haxo ◽  
W. R. Bingham
Keyword(s):  
Physical Properties ◽  
Heterogeneous Catalysts ◽  
Accelerated Aging ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Ethylene Propylene ◽  
Aging Properties ◽  
Aluminum Halide ◽  
Catalyst Systems ◽  
Catalyst Efficiency

Abstract Soluble catalyst systems derived from alkyl aluminum halides in combination with vanadium oxytrichloride or tetrachloride produce highly random ethylene-propylene copolymers with high catalyst efficiency. By the choice of the alkyl aluminum halide and molar ratio of aluminum to vanadium, variations in polymerization efficiency and molecular weight are possible. The copolymers prepared with these soluble catalysts show advantages in both processing and physical properties over those prepared with heterogeneous catalysts. Vulcanizates of these copolymers show somewhat different accelerated aging properties depending on the additive used along with the peroxide. Low temperature properties of copolymers containing less than 70 weight % propylene show a tendency for crystallization which is not shown by X-ray diffraction. Overall physical properties and tire tests show some preference for the 65 weight % propylene copolymer over the 50% material.

TESTING HYPOTHESES ABOUT ABSOLUTE CONCENTRATION CURVES AND MARGINAL CONDITIONAL STOCHASTIC DOMINANCE

2008 ◽  
Vol 24 (4) ◽  
pp. 1044-1062 ◽  
Author(s):  
Edna Schechtman ◽  
Amit Shelef ◽  
Shlomo Yitzhaki ◽  
Ričardas Zitikis
Keyword(s):  
Simulation Study ◽  
Stochastic Dominance ◽  
Statistical Tests ◽  
Distribution Functions ◽  
The Other ◽  
Absolute Concentration ◽  
Testing Hypotheses ◽  
Theoretical Considerations ◽  
Concentration Curves ◽  
Economic Studies

We consider statistical tests concerning various relationships between two absolute concentration curves (ACCs). In particular, we consider tests for determining if the two ACCs coincide, if one is above another in a specified order, or if they do not intersect without specifying which one is above/below the other one. These problems are of interest in the context of marginal conditional stochastic dominance (MCSD). Constructing statistical tests for the MCSD relies on ideas and also on their modifications developed by Linton, Maasoumi, and Whang (2005, Review of Economic Studies 72, 735–765) in the context of stochastic dominance for distribution functions. Our theoretical considerations are supplemented with a simulation study.

scholarly journals Studying Reactivity Relationships of Copolymers N-naphthylacrylamide with (Acrylicacid and Methylacrylate)

2019 ◽  
Vol 16 (2) ◽  
pp. 0345
Author(s):  
Ameen Hadi Mohammed
Keyword(s):  
Fourier Transform ◽  
Thermal Properties ◽  
Infrared Spectroscopy ◽  
Free Radical ◽  
Statistical Method ◽  
Benzoyl Peroxide ◽  
Elemental Analysis ◽  
Reactivity Ratios ◽  
Sequence Distribution ◽  
Ft Ir

            The organation ⁄monomer N-naphthylacrylamide (NAA) was prepared; subsequently the synthesized monomer was successfully copolymerized with acrylicacid (AA) and methylacrylate (MA) by free radical technique using dry benzene as solvent and benzoyl peroxide (BPO) as initiator. The overall conversion was kept low (≤ 10% wt/wt) for all studies copolymers samples. The synthesized monomer and copolymers were characterized using Fourier transform infrared spectroscopy (FT-IR), and their thermal properties were studied by DSC and TGA. The copolymers compositions were determined by elemental analysis. Kelen-Tudes and Finmman-Ross graphical procedures were employed to determine the monomers reactivity ratios. The derived reactivity ratios (r1, r2) are: (0.048, 0.687) for (NAA-co-AA) and (0.066, 0.346) for (NAA-co-MA). Based on the average reactivity ratios, sequence distribution of monomers in the copolymers and the microstructure of copolymers were calculated by statistical method and found that these values are in agreement with the derived reactivity ratios.

scholarly journals Structural and Thermal Properties of Ethylene-Norbornene Copolymers Obtained Using Vanadium Homogeneous and SIL Catalysts

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2433
Author(s):  
Paweł Groch ◽  
Anna Bihun-Kisiel ◽  
Aleksandra Piontek ◽  
Wioletta Ochędzan-Siodłak
Keyword(s):  
Thermal Properties ◽  
Reactivity Ratio ◽  
Proton Nuclear Magnetic Resonance ◽  
Sequence Length ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Copolymer Microstructure ◽  
Chain Termination Reaction ◽  
Catalyst Systems

The series of ethylene-norbornene (E-NB) copolymers was obtained using different vanadium homogeneous and supported ionic liquid (SIL) catalyst systems. The 13C and 1H NMR (carbon and proton nuclear magnetic resonance spectroscopy) together with differential scanning calorimetry (DSC) were applied to determine the composition of copolymers such as comonomer incorporation (CNB), monomer dispersity (MD), monomer reactivity ratio (re), sequence length of ethylene (le) and tetrad microblock distributions. The relation between the type of catalyst, reaction conditions and on the other hand, the copolymer microstructure, chain termination reaction analyzed by the type of unsaturation are discussed. In addition, the thermal properties of E-NB copolymers such as the melting and crystallization behavior, like also the heterogeneity of composition described by successive the self-nucleation and annealing (SSA) and the dispersity index (DI) were determined.

Photodegradation of Ethylene/Propylene/Polar Monomers Co‐ and Terpolymers. I—Prepared by Group 4 Catalyst Systems

2005 ◽  
Vol 42 (9) ◽  
pp. 1259-1270
Author(s):  
Susete Fernandes ◽  
Sandra Correia ◽  
A. Vishwa Prasad ◽  
K. Raghunatha Reddy ◽  
S. Rana ◽  
...  
Keyword(s):  
Ethylene Propylene ◽  
Group 4 ◽  
Polar Monomers ◽  
Catalyst Systems

scholarly journals The kinetics of the interaction of atomic hydrogen with olefines IV. Results obtained by the foregoing techniques

1949 ◽  
Vol 196 (1047) ◽  
pp. 494-509 ◽  
Keyword(s):  
Double Bond ◽  
Hydrogen Atom ◽  
Atomic Hydrogen ◽  
Experimental Techniques ◽  
Effective Diameter ◽  
Collision Efficiency ◽  
Ethylene Propylene ◽  
Theoretical Considerations ◽  
Kinetics Of ◽  
Effect Of Structure

The experimental techniques and theoretical considerations developed in the previous parts have been utilized in obtaining data on the reactions of the type H + C n H 2 n = C n H 2 n +1 . The olefines used were ethylene, propylene, iso -butene, n -pentene-2 ( cis ), and 2, 3, 3, tri-methyl-butene-1. Certain tentative suggestions as to the effect of structure on the reactivity of the double bond are put forward, but in general, the collision efficiency of a hydrogen atom with an olefine lies between 10 –3 and 10 –4 . It is noted that in the computation of the collision efficiency, it seems to be rather unsatisfactory that the diameter of the whole molecule should be used and it is suggested that perhaps the effective diameter of a more intimate part of the molecule in the region of the double bond should be employed.

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