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Badania nad polikondensacją pochodnych chloronitrobenzeny z siarczkami sodu w N-metylo-2-pirolidonie

Polus I.

Wiadomości Chemiczne

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2003

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[Z] 57, 1-2

63--73

EN

Poly (phenylene sulfides) are oligomeric materials with excellent plastic performance of commercial interest. They form durable insulating coatings and are cementing agents. The products of medium molecular weight, containing oligomers up to octamers, are formed by the reaction of sulfur or sodium sulfide with para-substituted chlorobenzenes [2, 29]. The reaction is not a simple stepwise polycondensation. HS( formed in a one-electron transfer process initiates the chain formation and the reaction goes with reactive intermediate radicals and radical cations. This reaction can be called the reactive intermediate polycondensation. The reaction temperature must be higher than 150o C to cleave the disulfide linkage homolytically allowing surviving the chain forming carriers. In this paper I report the reaction of chloronitrobenzene derivatives with sodium sulfide and disulfide in polar solvents. The reaction carried out in this solvent gives the highest reaction rate and leads to products with relatively high molecular weight. An activation of N-methyl-2-pyrrolidone molecule to a radical form by a transfer of electron from HS- (scheme 3) [27]. In the reaction of 1-chloro-4-nitrobenzene with sodium sulphide or disulphide in N-methyl-2-pyrrolidone at high temperatures oligomeric products were obtained [3]. The mechanism of the reactive intermediates polycondensation reaction are described. The reaction of 1-chloro-4-nitrobenzene with sodium sulphide and disulphide in N-methyl-2-pyrrolidone proceeds as follows: the first stage is the substitution of sulphur for chlorine. In the second stage there is a progressive reduction of nitro groups.

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EPR and ESEEM Identification of Free Radicals and Molecular Structure of the Oligomers Formed During Polycondensation of 1-Chloro-4-nitrobenzene with Sodium Sulfides in N-Methyl-2-pyrrolidone

Hoffmann S., Polus I., Hilczer W., Goslar J., Kiczka S., Doczekalska B.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 1

87-98

EN

The synthesis of derivative of poly (4-hydrazo-diphenylenedisulfide) by reaction of 1-chloro-4-nitrobenzene with sodium sulfide and disulfide in N-methyl-2-pyrrolidone leads to oligomeric products with average molecular weight of the homogeneous chains 1182 g/mol and 690 g/mol, respectively. The mechanisms of the reactive intermediates polycondensation reaction are described. The products were characterized by IR, 1H NMR, and EPR spectroscopy and by elemental analysis. The final amorphous oligomer products contain mostly diamagnetic species and about 1% of paramagnetic species. The latter produce strong isotropic EPR signal at g = 2.0025 from free radical with concentration of about 1018 radicals/gram. Pulsed EPR spectroscopy allowed identifying the radical by analysis of the electron spin echo envelope modulation spectrum. The radical is localized on the carbon atom of the C=O-group of the N-methyl-2-pyrrolidone moiety with broken internal C-N bond of the lactam ring.

3

Synthesis of New Sulfenic Acid Anilides from Aromatic Disulphides in the Presence of Silver Nitrate

Doczekalska B., Wejchan-Judek M., Polus I.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 6

895-897

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Trimerization of 3-isocyanatomethyl-3/5A5-trimethylcyclohexyl isocyanate (IPDI)

Wejchan-Judek W., Polus I., Doczekalska B., Pertek H.

Polimery

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2001

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T. 46, nr 2

131-132

EN

Trimerization of IPDI was studied in relation to catalyst type and reaction temperature. 2,4,6-tris(Dimethylaminomethyl)phenol (DMP-30), potassium acetate (K 64), l,4-diazabicyclo[2.2.2]octane (DABCO), tetrabutyl orthotitanate (TBT), and a DMP-30/K 64 binary system were used as catalysts (used in 1, 2 or 5% based on IPDI weight). When dissolved in butyl acetate and stirred for 1 h at 80°C with 5% of DMP-30, IPDI yielded a trimer melting at 286-289°C (Table 1). The most active catalyst was K 64 (added 1% by wt., as a solution in ethyl acetate containing 15% of K): in 1 h at 80°C, a trimer was obtained in 98% yield. TBT (1%, 5%), DMP-30 (1%), DABCO, and K 64 (1%, 23°C) proved to be inactive as catalysts. In the binary system studied, the DMP-30 was found to inhibit the catalytic action of the K 64 consistuent.

PL

Badano przebieg trimeryzacji IPDI w zależności od rodzaju katalizatora i temperatury reakcji. Jako katalizatory (1, 2 lub 5% mas. w przeliczeniu na IPDI) zastosowano 2,4,6-tris(di-metyloaminometylo)fenol (DMP-30), octan potasu (K 64), l,4-diazabicyklo[2.2.2]oktan (DABCO), ortotytanian tetrabutylu (TBT) oraz układ dwuskładnikowy DMP-30/K 64. IPDI rozpuszczony w octanie butylu i mieszany w ciągu 1 h (temp. 80°C) z 5% DMP-30 tworzy trimer o tt. 286-298"C (tabela 1). Najaktywniejszym katalizatorem okazał się K 64 (w postaci roztworu w octanie etylu zawierającego 15% K), dodawany w ilości 1% mas. w przeliczeniu na IPDI; pozwala on na otrzymanie (lh, temp. 80°C) trimeru z wydajnością 98%. TBT (1%, 5%), DMP-30 (1%), DABCO oraz K 64 (1%, temp. 23°C) okazały się nieaktywne jako katalizatory. W układzie dwuskładnikowym DMP-30/K 64, DMP-30 inhibituje katalityczne działanie K 64.