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Reatarding effect of nitrogen ylide for the polymerization of N-vinyl pyrrolidone (1990)

Vasishtha, R. ; Kumar, P. ; Awasthi, S. K. ; [weitere]

Springer

Colloid & polymer science 268 (1990), S. 645-648

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ISSN: 1435-1536

Schlagwort(e): β-picolinium-p-chlorophenacylide ; α-α azobisisobutyronitrile ; N-vinyl pyrrolidone ; dilatometry ; retarder ; kinetics

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie , Maschinenbau

Notizen: Abstract β-Picolinium-p-chlorophenacylide (β-PCFY) acts as a retarder for polymerization of N-vinyl pyrrolidone. The polymerization runs were carried out at 60°C using benzene as an inert solvent. The kinetic equation for the present system may be written asR p α[β-PCPY]−1.0 [AIBN]0.66[N-VP]1.0. The value of overall energy of activation for polymerization in presence and absence ofβ-PCPY was computed as 44.0 and 42.3 kJ mol−1, respectively. The inverse relationship ofR p and¯M v withβ-PCPY suggests thatβ-PCPY acts as a polymerization retarder. The retarding effect is also evidenced by higher initiator exponent value and higher value of energy of activation in presence of ylide. A mechanism is also proposed in which polymer propagating chain combines with one ylide component to give resonance stabilized radical.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01410406

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Digitale Medien

p-acetyl benzylidene triphenylarsonium ylide initiated radical terpolymerization of styrene, acrylonitrile and copper acrylate: synthesis, characterization and properties (1996)

Shukla, Prerna ; Srivastava, A. K.

New York, NY [u.a.] : Wiley-Blackwell

Polymer International 41 (1996), S. 407-412

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ISSN: 0959-8103

Schlagwort(e): terpolymerization ; kinetics ; thermal properties ; arsonium ylide ; styrene ; acrylonitrile ; copper acrylate ; Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: Solution terpolymerization of styrene (Sty), acrylonitrile (AN) and copper acrylate (CuA) has been carried out in dimethylformamide at 90°C for 4 h using p-acetyl benzylidene triphenylarsonium ylide as radical initiator. 1H nuclear magnetic resonance (NMR), IR and elemental analysis have been used to characterized the terpolymer. Analysis of kinetic data indicates the following rate equation: $$R_{\rm p} \propto \left[ {{\rm ylide}} \right]^{0.5} \left[ {{\rm Sty}} \right]\left[ {{\rm AN}} \right]{1 \over {\left[ {{\rm CuA}} \right]}}$$ The overall activation energy is 38 kJ mol-1. The composition of terpolymer calculated from NMR and elemental analysis has been used to evaluate reactivity ratios as r1(Sty) = 5 ± 2 and r2(AN + CuA) = 0.4 ± 0.02 employing the Finemann-Ross method, which confirms its random origin. The terpolymer was thermally stable up to 2007deg;C.

Zusätzliches Material: 10 Ill.

Materialart: Digitale Medien

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Digitale Medien

Copolymerization of zinc acrylate with acrylonitrile initiated by As2S3-styrene complex (1994)

Agrawal, B. P. ; Srivastava, A. K.

New York, NY [u.a.] : Wiley-Blackwell

Polymer International 34 (1994), S. 105-109

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ISSN: 0959-8103

Schlagwort(e): Zinc acrylate ; acrylonitrile ; As2S3-styrene complex ; copolymerization ; dilatometry ; kinetics ; Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: Radical copolymerization of zinc acrylate (ZnA2) with acrylonitrile (AN), initiated by As2S3-styrene complex(I), in dimethyl Sulphoxide (DMSO) at 90 ± 0.1°C for 1.0h under inert atmosphere, yields non-alternating copolymers. The kinetic expression is Rp ∝ [I]0.33 [ZnA2]0.25 [AN]0.44, i.e. the system follows non-ideal kinetics, which is due to primary radical termination as well as degradative chain transfer reactions. The values for activation energy (E) and k2p/kt are 128kJ mol-1 and 8.57 × 10-7 litre mol-1 s-1, respectively. Thermal stability, solubility in different solvents, and IR and NMR spectra have been evaluated.

Zusätzliches Material: 5 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/pi.1994.210340114

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