Amphiphilic polymethacrylates as crosslinked polymer precursors obtained by free‐radical monomethacrylate/dimethacrylate copolymerizations

Matsumoto, Akira; Ohashi, Tomonori; Oe, Hiroaki; Aota, Hiroyuki; Ikeda, Jun‐Ichi

doi:10.1002/1099-0518(20001215)38:24<4396::aid-pola80>3.3.co;2-k

Cited by 4 publications

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“…2 The validity of FS theory was confirmed by conducting the freeradical cross-linking monovinyl/divinyl copolymerizations 40 under the polymerization conditions in which the significance of the thermodynamic excluded volume effect and intramolecular crosslinking, the respective primary and secondary factors for the greatly delayed gelation, 33a was removed; thus, the polymerization conditions were adjusted as follows: (a) a small amount of cross-linker and a high monomer concentration and (b) a small amount of chain transfer agent should be required to estimate a high theoretical gel point and to keep the primary polymer chain length constant, respectively. We extended the above discussion of network formation mechanism to the preparation of novel amphiphilic polymers, 41 as the precursors of the homogeneous cross-linked monovinyl/divinyl copolymers, and, furthermore, amphiphilic network polymers 42 biased toward the ideal network polymer governed by FS theory.…”

Section: Introductionmentioning

confidence: 99%

Discussion of “Greatly Delayed Gelation from Theory in Free-Radical Cross-Linking Multivinyl Polymerization Accompanied by Microgel Formation” Based on Multiallyl Polymerization

et al. 2010

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In free-radical cross-linking (co)polymerization of common multivinyl monomers it has been conceived that the greatly delayed gelation from theory is due to microgel formation. This was discussed by pursuing the gelation in free-radical cross-linking polymerization of diallyl terephthalate (DAT) in the coexistence of a preceded cross-linking polymerization of ethylene glycol dimethacrylate accompanied by in situ methacrylate network-polymer-precursor (NPP) formation since in DAT polymerization the primarypolymer-chain forming reaction could be controlled by the allylic hydrogen abstraction of growing polymer radical from allyl monomer, and thus, any gel effect inducing the complication of the polymerization system is not observed at all. Thus, the preceded in situ methacrylate NPP formation promoted the gelation, never leading to delayed gelation. The role of high-molecular-weight NPPs ranging from an ideal NPP to a nanogellike NPP on the gelation in DAT polymerization was then pursued by SEC-MALLS-viscometry; the addition of high-molecular-weight NPPs clearly promoted the gelation, and strikingly, the role of nanogel-like NPP was never as an inactive polymer particle leading to a delayed gelation.

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Section: Introductionmentioning

confidence: 99%

Discussion of “Greatly Delayed Gelation from Theory in Free-Radical Cross-Linking Multivinyl Polymerization Accompanied by Microgel Formation” Based on Multiallyl Polymerization

et al. 2010

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“…d ‐Bornyl methacrylate (BoMA) was chosen as a typical example of bulky monomethacrylate monomers, the polymerization of which leads to the formation of rigid polymer chain. Besides, this work provides useful information for a full understanding of three‐dimensional network formation in free‐radical crosslinking monovinyl/divinyl copolymerizations as part of our continuing studies aimed at the elucidation of the crosslinking polymerization mechanism and the control of network formation to molecularly design a variety of network polymers 1, 33–37…”

Section: Introductionmentioning

confidence: 99%

Effect of primary polymer chain rigidity on intramolecular cyclization and intramolecular crosslinking in free‐radical crosslinking monomethacrylate/dimethacrylate copolymerizations

Ikeda

Hasei

Yasuda

et al. 2004

J of Applied Polymer Sci

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d-Bornyl methacrylate (BoMA) was chosen as a typical example of bulky monomethacrylate monomers, the polymerization of which led to the formation of a rigid polymer chain. To discuss the effect of primary polymer chain rigidity on intramolecular cyclization, we compared the solution copolymerization results of BoMA with 1 mol % ethylene dimethacrylate (EDMA; n ϭ 1) and poly(ethylene glycol dimethacrylate) [CH 2 AC(CH 3 )CO(OCH 2 CH 2 ) n OC-OC(CH 3 )ACH 2 , n ϭ 9 (PEGDMA-9)] with those of methyl methacrylate (MMA) with 1 mol % EDMA and PEGDMA-9; the dependence of the weight-average degree of polymerization on conversion for the former BoMA copolymerization systems was completely opposed to that for the latter MMA systems, and this was a reflection of a reduced occurrence of intramolecular cyclization caused by the rigidity of the primary polymer chain. The effect of primary polymer chain rigidity on intramolecular crosslinking was discussed through a comparison of both BoMA/EDMA and MMA/ EDMA copolymerizations. The correlations of the intrinsic viscosity, root-mean-square (rms) radius of gyration, and second virial coefficient with the molecular weight were examined for both BoMA/EDMA (90/10) and MMA/ EDMA (90/10) copolymerizations in a dilute solution because microgelation was observed in solution MMA/EDMA (90/10) copolymerization as a reflection of a locally extensive occurrence of intramolecular crosslinking. The logarithmic plots of both the intrinsic viscosity and rms radius of gyration versus the molecular weight for MMA/EDMA copolymerization were compared with those for the corresponding BoMA/EDMA copolymerizations. The second virial coefficients were greater than 10 Ϫ5 mol cm 3 g Ϫ2 for BoMA/EDMA copolymers, even when the conversion was very close to the gel point, whereas they were quite low, that is, less than 10 Ϫ5 mol cm 3 g Ϫ2 , for an MMA/EDMA copolymer obtained at more than 15% conversion. These were ascribed to a suppressed occurrence of intramolecular crosslinking, a reflection of the lessened flexibility of the polymer main chain and a steric effect due to the bulky d-bornyl groups.

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“…The solvent component dependencies of the swelling ratios were characteristic of novel amphiphilic gels. In this connection, the present article deals with the novel amphiphilic network polymers consisting of polar, short primary polymer chains and nonpolar, long cross-link units as the opposite case of the previous work . Thus, 2-hydroxyethyl methacrylate (HEMA), a polar monomer having a hydroxyl group, was copolymerized radically with 5 mol % heneicosapropylene glycol dimethacrylate [CH 2 C(CH 3 )CO(OCH(CH 3 )CH 2 ) 21 OCOC(CH 3 )CH 2 , PPGDMA-21], a nonpolar monomer having a poly(oxypropylene) unit, in the presence of LM.…”

Section: Introductionmentioning

confidence: 99%

“…Certainly, the cross-linked polymer should change from a homogeneous network structure biased toward the ideal network polymer to an inhomogeneous one biased toward the microgel, the formation of which depends on the polymerization conditions. 1 Thereafter, we extended the above mechanistic discussion based on multiallyl polymerization to the preparation of novel amphiphilic polymers 28 as the precursors of the homogeneous cross-linked polymers biased toward the ideal network polymer in the freeradical cross-linking monovinyl/divinyl copolymerization by introducing an oligomeric, long cross-linker such as tricosaethylene glycol dimethacrylate [CH 2 d C(CH 3 )CO(OCH 2 CH 2 ) 23 OCOC(CH 3 )dCH 2 , PEGDMA-23] and concurrently, forming oligomeric, short primary polymer chains in the presence of LM as a chain transfer agent, in which both lengths of primary polymer chain and cross-link unit are in a comparable order. Here benzyl methacrylate (BzMA) was used as a monovinyl monomer because BzMA forms rather rigid, nonpolar primary polymer chains and PEGDMA-23 as a crosslinker contains a flexible, polar poly(oxyethylene) unit leading to novel amphiphilic polymers as vinyl-type network-polymer precursors.…”

Section: Introductionmentioning

confidence: 99%

“…In this connection, the present article deals with the novel amphiphilic network polymers consisting of polar, short primary polymer chains and nonpolar, long cross-link units as the opposite case of the previous work. 28 Thus, 2-hydroxyethyl methacrylate (HEMA), a polar monomer having a hydroxyl group, was copolymerized radically with 5 mol % heneicosapropylene glycol dimethacrylate [CH 2 dC(CH 3 )CO(OCH-(CH 3 )CH 2 ) 21 OCOC(CH 3 )dCH 2 , PPGDMA-21], a nonpolar monomer having a poly(oxypropylene) unit, in the presence of LM. The resulting amphiphilic gels, schematically depicted in Figure 1, were characterized by measuring their swelling ratios in various types of mixed solvents.…”

Section: Introductionmentioning

confidence: 99%

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Novel Amphiphilic Network Polymers Consisting of Polar, Short Primary Polymer Chains and Nonpolar, Long Cross-link Units Obtained by Free-Radical Cross-linking Monomethacrylate/Dimethacrylate Copolymerizations

et al. 2003

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Solution copolymerizations of 2-hydroxyethyl methacrylate (HEMA), a polar monomer having a hydroxyl group, with 5 mol % (corresponding to 35.7 wt %) heneicosapropylene glycol dimethacrylate (PPGDMA-21), a nonpolar monomer having a poly(oxypropylene) unit, were carried out in MeOH at a dilution of 2/3 in the presence of different amounts of lauryl mercaptan as a chain transfer agent, providing novel amphiphilic vinyl-type network polymers consisting of polar, short primary polymer chains and nonpolar, long cross-link units. The vinyl-type network polymers formed via highly branched prepolymers have abundant dangling chains as their characteristic feature, especially when the primary polymer chain length is short, because both terminal parts of primary polymer chain would be dangling chains. The amphiphilicity of the resulting gels was checked by measuring their swelling ratios in the mixed solvents consisting of nonpolar tert-butylbenzene (t-BB) and polar MeOH; thus, with an increase in the MeOH volume percent, the gels shrank to the smallest swelling ratio at the start point (i.e., in pure t-BB), swelled gradually and then rather sharply beyond 20 vol %, reached the maximum swelling at about 70 vol %, and then shrank gradually up to a rather high swelling ratio at the terminal (i.e., in pure MeOH). The profiles of the solvent component dependencies of the swelling ratios are characteristic of novel amphiphilic gels. The conversion dependency of the characteristic swelling behavior suggests that the response of the gel obtained at an earlier stage of gelation was sharper than that of the gel obtained at a late stage of gelation. The influence of H 2O on the characteristic swelling behavior of resulting amphiphilic gels was examined by measuring their swelling ratios in the mixed solvents consisting of MeOH/H2O or acetone/ H2O in order to collect information about the role of cross-link units on the swelling behavior of amphiphilic gel.

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Amphiphilic polymethacrylates as crosslinked polymer precursors obtained by free‐radical monomethacrylate/dimethacrylate copolymerizations

Cited by 4 publications

References 0 publications

Discussion of “Greatly Delayed Gelation from Theory in Free-Radical Cross-Linking Multivinyl Polymerization Accompanied by Microgel Formation” Based on Multiallyl Polymerization

Discussion of “Greatly Delayed Gelation from Theory in Free-Radical Cross-Linking Multivinyl Polymerization Accompanied by Microgel Formation” Based on Multiallyl Polymerization

Effect of primary polymer chain rigidity on intramolecular cyclization and intramolecular crosslinking in free‐radical crosslinking monomethacrylate/dimethacrylate copolymerizations

Novel Amphiphilic Network Polymers Consisting of Polar, Short Primary Polymer Chains and Nonpolar, Long Cross-link Units Obtained by Free-Radical Cross-linking Monomethacrylate/Dimethacrylate Copolymerizations

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