scholarly journals Copolymer composition control policies for semibatch free radical copolymerization processes

1989 ◽  
Vol 37 (5) ◽  
pp. 1429-1433 ◽  
Author(s):  
K. Y. Choi
1972 ◽  
Vol 50 (11) ◽  
pp. 1757-1766 ◽  
Author(s):  
Alfred Rudin ◽  
Schumann S. M. Chiang ◽  
H. Kirk Johnston ◽  
Paul D. Paulin

The free radical copolymerization of methacrylonitrile, styrene, and α-methylstyrene was studied at 60 °C in toluene solution. Copolymer composition was calculated from the composition of the unreacted monomers, as measured by g.l.c. Reactivity ratios measured previously for the three monomer pairs involved were used with the simple terpolymerization equation to predict polymer composition. Agreement between predicted and experimental polymer compositions was satisfactory. The behavior of α-methylstyrene can be described by a simple model without reference to ceiling temperature or penultimate effects because sequence lengths of this monomer in the terpolymers are short.A true azeotropic feed composition was not investigated, but several monomer mixtures produced copolymers with compositions which varied so little from that of the feed that the systems could be considered to be azeotropic for practical synthetic purposes. This behavior is in accord with expectations.Analytical accuracy of the gas chromatographic techniques was examined and means are suggested to make the best use of this method in copolymerization studies.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Inga Woecht ◽  
Gudrun Schmidt-Naake

AbstractFree radical copolymerization of styrene (S) and acrylonitrile (AN) in the ionic liquids (ILs) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), 1,3-dimethylimidazolium dimethylphosphate ([MMIM]Me2PO4) and 1-ethyl-3- methylimidazolium ethylsulfate ([EMIM]EtSO4) were investigated. 2,2’-azobisiso butyronitrile (AIBN) and dibenzoyl peroxide (BPO) were used as initiators and dimethyl formamide (DMF) and methanol as reference solvents. The influence of the viscosity on the conversion and the molecular weights was studied by variation of the reaction temperature and the IL concentration. At reaction temperatures of 80 - 85 °C already after 30 minutes a conversion of about 80 % and almost a doubling of the molecular weights is reached for the S/AN (50/50 mol%) copolymerization. In addition the copolymerization behavior of S/AN in [EMIM]EtSO4 was investigated. With increasing concentration of AN in the monomer feed the polymerization rate as well as the molecular weights of the copolymers increase. The influence of the ionic liquid on the copolymer composition, glass-transition temperature and rheological behavior was studied.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Ewa Wiśniewska ◽  
Barbara Pabin–Szafko

AbstractTelechelic vinyl oligomers terminated with hydroxyl groups were prepared by free radical copolymerization of styrene (S) and acrylonitrile (AN), initiated by azoester-2,2’-azobis[2-methyl-ω-hydroxy-oligo(oxyethylene) propionate] [AIB-OOE(400)], carried out in N,N-dimethylformamide. The reactivity ratios rS=0,225 and rAN=0,722 for styrene and acrylonitrile, respectively, were evaluated by Kelen-Tüdős method. The glass transition temperatures (Tg) of the copolymers were determined by differential scanning calorimetry. Tg values varied with the copolymer composition in the range of 60-82 °C and the maximum Tg value was obtained for copolymer with 60 mol% AN.


2018 ◽  
Vol 219 (14) ◽  
pp. 1800084 ◽  
Author(s):  
Miguel Rosales-Guzmán ◽  
Odilia Pérez-Camacho ◽  
Román Torres-Lubián ◽  
Simon Harrisson ◽  
Ulrich S. Schubert ◽  
...  

Author(s):  
S. V. Badanov ◽  
A. V. Urumov ◽  
V. V. Bayandin ◽  
N. S. Shaglaeva

The copolymers of 2,3-Dichloropropene with vinyl chloride, methyl methacrylate, and styrene of different compositions were obtained via free-radical copolymerization. The copolymerization constants for the comonomers were found from the dependence of the copolymer composition on the initial mixture content. An increase in the content of 2,3-Dichloropropene in the initial mixture was found to decrease the yield and intrinsic viscosity of the copolymer for all systems. The reactivity of 2,3-Dichloropropene in copolymerization reactions was assessed according to the reciprocals of the copolymerization constants of vinyl chloride, methyl methacrylate, and styrene, which indicate the reactivity of the dichlorinated monomer when interacting with comonomer radicals. It was found that 2,3-dichloropropene is the most active in the reaction with a styrene radical. However, its reactivity with a methyl methacrylate radical decreases by a factor of 0.88 as compared to the styrene radical. The lowest reactivity of 2,3-Dichloropropene is observed when interacting with a vinyl chloride radical. The synthesized copolymers can be further modified by replacing chlorine atoms with functional groups.


1996 ◽  
Vol 197 (12) ◽  
pp. 4119-4134 ◽  
Author(s):  
Michael Buback ◽  
Thomas Dröge ◽  
Alex Van Herk ◽  
Frank-Olaf Mähling

2017 ◽  
Vol 50 (9) ◽  
pp. 3516-3523 ◽  
Author(s):  
A. Zarrouki ◽  
E. Espinosa ◽  
C. Boisson ◽  
V. Monteil

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39522-39529 ◽  
Author(s):  
Wanfen Pu ◽  
Daijun Du ◽  
Rui Liu ◽  
Jiongyi Gu ◽  
Kewei Li ◽  
...  

HDPAM was synthesized by water free-radical copolymerization based on functional hyperbranched polyamide-modified ultrafine silica as functional monomer.


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