The Fundamental Basis for Cyclopolymerization. IV. Radiation Initiated Solid-State Polymerization of Certain Dimethacrylamides

Butler, George B.; Myers, G. Rodney

doi:10.1080/00222337108061030

Cited by 44 publications

(7 citation statements)

References 15 publications

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“…We attempted to homopolymerize the monomers DMMAm and MAPYD under standard radical conditions without success. This is in agreement with previous studies concluding that N , N -disubstituted methacrylamides do not polymerize under radical conditions. − The reason for this is believed to be the monomer taking a twisted conformation due to steric effects, hence reducing the system’s π-conjugation, lowering the monomer’s reactivity.…”

Section: Discussionsupporting

confidence: 92%

“…Other research groups have also observed this negative polymerizability of N , N -dialkyl methacrylamides under radical conditions using peroxo- or azo-initiators. − It has been suggested that the monomer takes a twisted conformation in which the vinyl and carbonyl groups are no longer in one plane due to steric hindrance between the substituents on the nitrogen and the methyl or vinyl group. , This twisted conformation is likely to reduce the system’s π-conjugation, giving a less stable radical intermediate, hence increasing the necessary heat of activation and significantly lowering of the monomer’s ability to polymerize. Anionic homopolymerization of MAPYD has been reported; however, quantitative yields were not obtained .…”

Section: Resultsmentioning

confidence: 96%

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N-Alkyl Methacrylamide Polymers as High Performing Kinetic Hydrate Inhibitors

2019

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Homo- and copolymers of N-alkyl methacrylamides with varying alkyl pendant groups have been synthesized and investigated for their performance as kinetic hydrate inhibitors (KHIs) in slow constant cooling experiments in rocking cells using a structure II-forming synthetic gas mixture at an initial pressure of 76 bar. We have tried to polymerize disubstituted N,N-dialkyl methacrylamides; however, these were found to not homopolymerize using radical initiators. For monosubstituted N-alkyl methacrylamides, the KHI performance was found to improve as the size of the alkyl pendant group increased from methyl to ethyl and then propyl (n- or iso-). The best performing homopolymer was poly(N-iso-propyl methacrylamide) (PIPMAm-I) which gave an onset temperature (average of 9 experiments) of 10.0 °C at 2500 ppm. The four structurally different N-butyl methacrylamides (n-, iso-, sec-, and tert-) were copolymerized with hydrophilic comonomers in order to investigate their potential as KHIs. The best performing copolymer containing butyl groups was a 1:1 copolymer of N-tert-butyl methacrylamide (tBuMAm) and N-methyl methacrylamide (MMAm) (P(tBuMAm-co-MMAm)), which gave an average onset temperature of 8.3 °C at 2500 ppm. The KHI performance of the N-propyl methacrylamide polymers (n- and iso-) was further investigated by adjusting the synthetic route. For example, poly(N-iso-propyl methacrylamide) (PIPMAm-IV) made and kept in n-butyl glycol ether (nBGE) as a 16.6 wt % solution gave an excellent performance, with an average onset temperature of 4.2 °C at a polymer concentration of 2500 ppm. The nBGE concentration was 12 500 ppm.

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Section: Discussionsupporting

confidence: 92%

Section: Resultsmentioning

confidence: 96%

N-Alkyl Methacrylamide Polymers as High Performing Kinetic Hydrate Inhibitors

2019

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“…As acrylamides have tunable hydrophilicity/hydrophobicity by one or two N -substituents, various thermo-responsive polymers based on acrylamides such as N -isopropylacrylamide [ 1 , 2 , 3 , 4 , 5 ] and N , N -diethylacrylamide (DEAA) [ 6 , 7 , 8 ] have been developed. On the other hand, N , N -disubstituted methacrylamides are poorly polymerizable both in radical and anionic polymerization [ 9 , 10 , 11 , 12 , 13 ], although they have acrylamide skeletons, where the vinylidene groups should be activated with the electron-withdrawing carbonyl groups. A difference between their typical monomer, N , N -dimethylmethacrylamide (DMMA), and the polymerizable analogue, N , N -dimethylacrylamide (DMAA), is the existence of an α-methyl group.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Thermo-Responsive Polymer via Radical (Co)polymerization of N,N-Dimethyl-α-(hydroxymethyl)acrylamide with N,N-Diethylacrylamide

Kohsaka

Tanimoto

2016

Polymers

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α-Functionalized acrylamides have not been considered as an effective monomer design due to their poor polymerizability, although the analogues, α-functionalized acrylates, are attractive monomers of which polymers exhibit characteristic properties. In this article, we report the first example of radical polymerization of α-functionalized N,N-disubstituted acrylamide affording thermo-responsive hydrophilic polymers. N,N-dimethyl-α-(hydroxymethyl)acrylamide (DMαHAA) was (co)polymerized with N,N-diethylacrylamide (DEAA). Although the homopolymerization did not afford a polymeric product, the copolymerizations with various feed ratios yielded a series of the copolymers containing 0%-65% of DMαHAA units. The obtained copolymers exhibited a lower critical solution temperature (LCST) in water; the cloud points (T c s) were linearly elevated as the contents of DMαHAA units from 32 to 64 • C, indicating that DMαHAA functioned as a more hydrophilic monomer than DEAA. The linear relationship between T c and DMαHAA content suggests that the homopolymer, poly(DMαHAA), should have T c at ca. 80 • C, although it is not available by direct radical homopolymerization.

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“…Contemporary experimental strategies to engineer MVMs for cyclopolymerization. Cyclopolymerization can be achieved by either using small DVMs (A) 87,[91][92][93]95,96,179 or by orienting the vinyl moieties close to one another through the use of a bulky template (Ba), [100][101][102][103][104][105][180][181][182][183] a metal template (Bc), [106][107][108] by exploiting hydrogen bonding (Bb) [110][111][112] or by constraining the reacting monomers in nanochannels (C) 115 . Figure 6.…”

Section: [H1] Emerging Biomedical Applicationsmentioning

confidence: 99%