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N‐tert‐butylacrylamide (NtBA) was copolymerized with ethylene glycol dimethacrylate (EDMA) in butanone solution over a wide composition and conversion range, using dibenzoyl peroxide (Bz2O2) as a free‐radical initiator. The copolymer composition was determined from the nitrogen content. Using only low conversion (≤20%) collected for the copolymerization reactions, monomer reactivity ratios were estimated using the Kelen‐Tudos graphical method and were found to be r1=0.26 (NtBA) and r2=7.05 (EDMA). In order to get a better insight into the mechanism of nanoporous copolymers of NtBA with EDMA preparation by thermal degradation of copolymers of N‐acryl‐N,N′‐di‐tert‐butylurea (A‐DitBuU) with EDMA, nonporous copolymers (model compound), of the same chemical structure and composition, were prepared by performing copolymerization of NtBA with EDMA up to the high conversion of 97–100%. Thermal behavior of nanoporous and nonporous copolymers of NtBA with EDMA was studied.

Synthesis and free‐radical initiated copolymerization of N‐acryl‐N,N′‐di‐tert‐butylurea (A‐DitBuU) with ethylene glycol dimethacrylate (EDMA) are described. The A‐DitBuU monomer was prepared by the condensation of acrylic acid to the N,N′‐di‐tert‐butylcarbodiimide (DitBuC) at room temperature. Copolymers of A‐DitBuU with EDMA of different monomer to monomer ratios in the feed were prepared in the presence of dibenzoyl peroxide (Bz2O2) in butanone at 70°C for 48 h up to a high conversion. The obtained crosslinked copolymers are insoluble in organic solvents. Copolymers thermal decomposition resulted in separation of tert‐butylisocyanate (C4H9NCO) in the temperature range between 180 and 280°C and by the formation of the thermally stable molecularly imprinted copolymers of N‐acryl‐N‐terc‐butylamide (A‐tBuA) with EDMA.

Copolymers of methacryl‐N,N′‐diisopropylurea (MA‐DiPrU) with ethylene glycol dimethacrylate (EDMA) at monomer‐to‐monomer ratios in the feed: 0.3/0.7; 0.5/0.5; 0.7/0.3; 0.8/0.2 were prepared in butanone in the presence of 2% of dibenzoyl peroxide (Bz2O2) at 70°C for 48 hr. Copolymers regardless of the ratio of comonomers in the feed decompose thermally at 200–250°C under the separation of isopropylisocyanate (iPrNCO). Residues after the removal of iPrNCO are thermally stable nanoporous crosslinked copolymers of methacryl‐isopropylamide (MA‐iPrA) with EDMA which decompose by a one‐step mechanism between 280°C and 450°C. Nonporous model copolymers poly(MA‐iPrA‐co‐EDMA) of similar composition, prepared by copolymerization of MA‐iPrA with EDMA, also decomposed by a one‐step mechanism as shown by TGA measurements.

Copolymers of methacryl‐dicyclohexylurea (MA‐DCU) with ethylene glycol dimethacrylate (EDMA) at monomer‐to‐monomer ratios in the feed: 0.3/0.7, 0.5/0.5, 0.7/0.3, 0.8/0.2 were prepared in butanone in the presence of 2% of dibenzoyl peroxide at 70°C for 48 hr. Copolymers, regardless of the ratio of comonomers in the feed, decompose thermally at 200–250°C under the separation of cyclohexylisocyanate (C6H11NCO). Residues after the removal of C6H11NCO are thermally stable nanoporous crosslinked copolymers of methacryl‐cyclohexylamide (MA‐CHA) with EDMA, which decompose by a one‐step mechanism between 300°C and 480°C.

Copolymerization of N-acryl-N,N′-dicyclohexylurea with ethylene glycol dimethacrylate or divinyl benzene in the presence of dibenzoyl peroxide as initiator gave corresponding crosslinked copolymers. Both copolymers thermally decompose by two-step mechanism. The first step separates cyclohexylisocyanate, thus forming the thermostable residue, which contains molecular imprints of cyclohexylisocyanates.

N-Acryl-N,N′-dicyclohexylurea (A-DCU) homopolymers and copolymers with styrene (St) are prepared under the standard free-radical-initiated polymerization. Copolymers of A-DCU with St prepared under different monomer-to-monomer ratios in the feed, have random composition with an azeotropic point at a ratio of 0.73 (A-DCU) to 0.27 (St). N-Methacryl-N,N′-dicyclohexylurea (MA-DCU) does not homopolymerize, but copolymerizes with St to randomly composed copolymers. Reactivity ratios determined by the Kelen-Tudos method are: r1 (A-DCU) = 0.80; r2 (St) = 0.50, and r1 (MADCU) = 0.18; r2 (St) = 4.84. All copolymers decompose under TGA conditions by a two step mechanism. In the first step, at a temperature of about 200°C separates cyclohexylisocyanate (C6 H11 NCO) under the formation of thermally stable poly(C6 H11 -acrylamido-co-St) and poly(C6 H11-methacrylamido-co-St) which decompose at a temperature of 450°C without the residue.

The title copolymers have been prepared by the free-radical-initiated copolymerization of 2-chlorostyrene (2-ClSt), 4-chlorostyrene (4-ClSt) and 2, 6-dichlorostyrene (2, 6-DClSt) with maleic anhydride (MAn) in toluene at 650C. Copolymers of chlorinated styrenes with MAn prepared under different monomer-to-monomer ratios in the feed have alternating composition. In all cases the mixture of comonomers forms charge-transfer complex monomers (CTC). Initial rate of copolymerization increases with the increase of electron donors in the comonomer feed, and the highest rates were at the equimolar ratios of comonomers in the feed. The thermal stability of the polymers was measured by thermogravimetric analysis in nitrogen. Homopolymers decompose by one-step mechanism while copolymers are more thermostable and decompose by two-step mechanism. Tg’s of homopolymers are lower than Tg’s of copolymers. The number and weight average molecular weights of chlorinated copolymers are higher than those of the corresponding homopolymers.

The free-radical-initiated copolymerization of 2,6-dichloro-styrene (2,6-DClSt), with maleimide (MI), N-methylmaleimide (NMeMI) and N-phenylmaleimide (NPhMI) was carried out in butanone or in toluene at 65°C with different monomer-to-monomer ratios in the feed. The copolymer composition was evaluated by chlorine content in polymers. The reactivity ratios determined by Kelen-Tudos method indicate the random arrangement of monomers in copolymer chains. In all studied systems, azeotropic points were observed at ratios of: 0.5 (2,6-DClSt) to 0.5 (MI) and 0.4 (2,6-DClSt) to 0.6 (NMeMI and NPhMI). Molecular weights of copolymer, which contain equimolar ratio of 2,6-DClSt-co-MI, NMeMI, and NPhMI are: Mw· 10−3 = 46.1; 90.4; 81.4. Mn 10−3 = 27.1; 46.0; 37.0. The copolymers are thermostable, film forming materials, which decompose by one-step mechanism between 400°C, and 500°C. The Tg's are linearly distributed between Tg's of homopolymers and in all cases, single well defined Tg's are obtained.

N(p-Phenoxy-phenyl)methacrylamide (PhOPhMAA) prepared by condensation of methacrylic acid anhydride with p-phenoxy-phe-nylamine readily homopolymerizes and copolymerizes with styrene (St) in the presence of azobisisobutyronitrile as initiator. The copolymers prepared under different monomer-to-monomer ratios in the feed have random composition with an azeotropic point at ratio f 0.65 (St) to 0.35 (PhOPhMAA). Reactivity ratios determined by Kelen-Tudos method are r 1 (St) = 0.61; r 2 (PhOPhMAA) = 0.55. Activation energy determined by Arrhenius method is 71.2 kJ mol -1 . Poly-PhOPhMAA and poly(PhOPhMAA-co-St) are thermally stable up to 350°C under TGA conditions. Tgs and higher transition temperatures are within the thermally stable region.

Synthesis and free-radical-initiated homopolymerization of phenoxy-phenylmaleimide (PhOPhMI) and copolymerization with styrene (St), (α-methylstyrene (αMeSt) and β–methylstyrene (β-MeSt) are described. It was found that alternating copolymers are formed under different monomer-to-monomer ratios in the feed and that the mechanism based on the participation of CT-complex best explains the formation of alternating copolymers. Equilibrium constants of CT-complexes are: K PhOPhMI/St = 0.20 Lmol−1; KPhOPhMI/αMeSt = 0.05 Lmol−1; KPhOPhMI/βMeSt = 0.02 Lmol−1. Homopolymer and co-polymers are film-forming materials, stable up to 350°C under TGA conditions. Tg s and higher transition temperatures are within the thermally stable region.

This paper describes synthesis and evaluation of polymeric additives for improving the flow properties of gas condensate. The additives were prepared by the free-radical initiated polymerization of methacryl esters with styrene and acrylic or methacrylic acid. Polymerization was performed by initiator azo-bis isobutyronitrile in toluene or xylene at 80 °C. The influence of additives structure, composition and molar weight, as well as gas condensate properties on its flow properties was studied. Gas condensate samples from the fields of Kalinovac, Stari Gradac and Molve located in the northern Croatia were used for evaluation of the prepared additives. It was found that the additives efficiency was considerably influenced by their properties and by condensate n-paraffin content and distribution.

The title compounds have been prepared by the addition of acrylic acid and methacrylic acid to dicyclohexylcarbodiimide (DCC). N-Acryl-N,N′-dicyclohexylurea (Acryl-DCU) homo-polymerizes and copolymerizes with α-methylstyrene (αMeSt), while Methacryl-DCU does not polymerize under the standard free-radical-initiated polymerization. Copolymers of Acryl-DCU with αMeSt prepared under different monomer-to-monomer ratios in the feed have random composition with an azeotropic point at ratio of 0.75 (Acryl-DCU) to 0.25 (αMeSt). Reactivity ratios determined by the Kelen-Tudos method are r1 (Acryl-DCU) = 0.72 and r2 (αMeSt) = 0.07. Poly(Acryl-DCU) and copolymers with αMeSt decompose under the TGA conditions by a two step mechanism. In the first step between 180 and 250°C, cyclohexylisocyanate separates by degradation of dicyclohexylurea in the side chain, while the thermally stable residue represents the poly(cyclohexylacrylamide) and copolymers with αMeSt.