摘要:

Diallyldimethylammonium chloride (DADMAC) was free-radical copolymerized with acrylamide (AA) in water at a total monomer concentration of 4 mol/L and 40°C with different monomer feed compositions. Gelation occurred only for 20/80 DADMAC/AA monomer feed although crosslinking was observed for all monomer feed compositions. The gel point was at 51% conversion, and the swelling ratios of the resulting gels were quite high, from 1400 to 700. Addition of 2‐propanol as a chain‐transfer reagent reduced crosslinking and prevented gelation. These results are mechanistically discussed in connection with the cyclopolymerizability of DADMAC, and significant allylic hydrogen abstraction by the growing polymer radical characteristic of allyl polymerization is proposed.

ISSN:0022-233X    

DOI:10.1080/00222338908052066

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Acrylamide‐vinyl alcohol (AAm/VA) graft copolymer was prepared and characterized. The interaction of the graft copolymer with poly‐(methacrylic acid) (PMAA) in water was studied by several experimental techniques, such as viscometry, potentiometry, conductometry, IR spectra, and transmittance measurements.PMAAwas found to interact with the graft copolymer in two distinct steps. The relative complexation ability of PAAm andPVAwith respect toPMAAdoes not change when these polymers are present as parts of a graft copolymer chain.

ISSN:0022-233X    

DOI:10.1080/00222338908052067

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Continuous thermodynamics is applied to the liquid‐liquid equilibrium in random copolymer blends. Two copolymers are mixed, each consisting of two different monomer units. Hence, up to four monomer units may be present in the system. Both copolymers are characterized by divariate distribution functions with respect to molecular weight (chain length) and chemical composition. The basic relations necessary for phase equilibrium calculations are derived. The influences of both polydispersities and of the different parameters included in the model for the excess Gibbs free energy are discussed by calculating cloud‐point curves and shadow curves. Applications to practical systems are given.

ISSN:0022-233X    

DOI:10.1080/00222338908052068

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In the anionic polymerization of methyl methacrylate (MMA) induced by imidazole (Im), an Im‐MMA adduct forms as an initiator adduct in methanol at 30°C in an argon atmosphere by the equimolar reaction of Im with theMMAmonomer. The additive effect of the adduct on the homopolymerization ofMMAin tetrahydrofuran at 30°C was investigated by dilatometry. The existence of the adduct increased the duration of the propagation step without shortening the formation step of the initiator adduct. The H‐D exchange reaction of the adduct was observed in D2O by1H NMR. Proton transfer of theMMAunit in the adduct was not observable until 45 h after initiation. The copolymerizability ofMMAwith acrylamide (AAm) induced by the Im catalyst in THF at 30°C was also investigated. It was found that the homo‐and copolymerizations proceeded at the same time. On the other hand, in theMMAhomopolymerization system, the addition of AAm monomer during the initial propagation step yielded copolymer of MMA and AAm for near equimolar concentration of the charged monomers.

ISSN:0022-233X    

DOI:10.1080/00222338908052069

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new method for deriving the initiation rate constant for a slowinitiated living polymerization process in which all reactions are first order with respect to all participants is presented. The method is based upon an approximate analytical solution of the set of differential equations modeling this class of processes. The solution is found by asymptotic expansion of the unknown functions, using a dimensionless parameter which characterizes the process.

ISSN:0022-233X    

DOI:10.1080/00222338908052070

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An approximate analytical solution of the set of differential equations modeling the anionic polymerization of styrene is presented. By using this solution, a new method for calculating the initiation rate constant for this polymerization process was developed.

ISSN:0022-233X    

DOI:10.1080/00222338908052071

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0022-233X    

DOI:10.1080/00222338908052065

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor