First Shell Substitution Effects in Hyperbranched Polymers:  Kinetic−Recursive Probability Analysis

Fradet, Alain; Tessier, Martine

doi:10.1021/ma070815t

Cited by 9 publications

(17 citation statements)

References 58 publications

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“…the reactivity of COOH group is decreased after the reaction of the OH groups present in the same monomer unit (the negative A–B substitution effect). The results presented here confirm the report of Fradet and Tessier that the AB branching factor, δ AB , can exert a considerable influence on the final polymer molar mass characteristics . Interestingly, the δ AB losses for DPE branched polymers are generally more than those for PE ones.…”

Section: Resultssupporting

confidence: 90%

“…Since the DB and M w are highly interdependent, it is important to estimate the effect of NSSE on M w and PDI . For this purpose, δ B , δ AB and M b are used, namely branching factors, which were introduced by Fradet and Tessier instead of Frey's DB . Parameters δ AB and δ B are average quantities that extend the concept of DB for AB 2 ‐type polymerizations to any type of polymerizations, including the AB 2 + B f system.…”

Section: Resultsmentioning

confidence: 99%

“…Values of δ can be used directly to calculate M w using Eqn as given by Fradet and Tessier:

M_{w} = \frac{M_{w}^{0} M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO}^{2})}{M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO})} + \frac{P true/ ((), 1 + n)}{M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO})}

\times ([], \frac{2 (1 - δ_{AB}) (M_{normalM} - M_{H 2 O}) (M_{normalb} - M_{H 2 O}) + δ_{normalB} {((), M_{M} - M_{normalH 2 normalO})}^{2}}{{(1 - δ_{AB})}^{2}})

M_{n}^{0} = \frac{M_{M} + n M_{C}}{n + 1}

M_{w}^{0} = \frac{M_{M}^{2} + n M_{C}^{2}}{M_{M} + n M_{C}}

…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, reducing the activity of functional groups in a monomeric unit, due to the reaction of other functional groups of the same monomer, which can also be interpreted as a negative substitution effect, is another hindrance to increasing the molar mass. This phenomenon was theorized by Fradet and co‐workers through introducing new branching factors for any type of HB polymer …”

Section: Introductionmentioning

confidence: 99%

“…This phenomenon was theorized by Fradet and co-workers through introducing new branching factors for any type of HB polymer. 21,22 Although there has been great progress in the synthesis and characterization of HB polymers with various core units, until now, no work has been published investigating the effect of core functionality on HBPE characteristics regarding both substitution and monomer self-condensation effects. The aim of the work reported here was to estimate molar mass characteristics, structure and composition of HB aliphatic polyester polyols based on bis-MPA and six-functional core molecule (dipentaerythritol) and compare these results with those of four-functional core (pentaerythritol)-based polymers synthesized in the same manner.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Study of negative substitution and monomer self‐condensation effects on molar mass and structural characteristics of hyperbranched polyesters originating from a high‐functionality core

Emamikia

Barikani

Bakhshandeh

2014

Polymer International

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

“…Values of δ can be used directly to calculate M w using Eqn as given by Fradet and Tessier:

M_{w} = \frac{M_{w}^{0} M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO}^{2})}{M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO})} + \frac{P true/ ((), 1 + n)}{M_{n}^{0} - ([], P true/ ((), 1 + n) M_{normalH 2 normalO})}

\times ([], \frac{2 (1 - δ_{AB}) (M_{normalM} - M_{H 2 O}) (M_{normalb} - M_{H 2 O}) + δ_{normalB} {((), M_{M} - M_{normalH 2 normalO})}^{2}}{{(1 - δ_{AB})}^{2}})

M_{n}^{0} = \frac{M_{M} + n M_{C}}{n + 1}

M_{w}^{0} = \frac{M_{M}^{2} + n M_{C}^{2}}{M_{M} + n M_{C}}

…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Study of negative substitution and monomer self‐condensation effects on molar mass and structural characteristics of hyperbranched polyesters originating from a high‐functionality core

Emamikia

Barikani

Bakhshandeh

2014

Polymer International

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show abstract

Relationship between structure and aromatic solvent permeability of crosslinked polyurethanes based on hyperbranched polyesters

2015

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This work investigates the relationship between structure and aromatic solvent permeability of polyurethanes based on trimethylolpropane (TMP) as a classical crosslinker and self‐made hyperbranched polyesters (HBPEs) as newly developed crosslinking agents. For this purpose three groups of samples were synthesized using toluene diisocyanate, poly(tetramethylene glycol) and different pseudo‐generation numbers of crosslinkers in the variable hard segment content. The results obtained from characterization tests indicate that replacing TMP by HBPE leads to an increase of crosslink density resulting in significant reduction of sorption capacity and conversely leads to an increase of the diffusion coefficient due to the lower glass transition temperature (Tg) of soft segments. In this way, the toluene permeability of hyperbranched polyurethane (HBPU) is considerably lower than that of classical polyurethane. The HBPUs with sufficient amount of hard segment have the lowest solvent uptake and diffusion coefficient leading to optimal barrier performance. By increasing the generation number of HBPE, the crosslink density of HBPU increases, but the crystallinity as well as Tg of soft segments decrease. These two contradictory changing trends of the structural characteristics cause a slight decrease in sorption coefficient of membranes and an increase of diffusivity. Therefore the barrier performance of HBPUs is weakened with increasing generation number of crosslinkers. © 2015 Society of Chemical Industry

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Nitrogen rich hyperbranched polyol via A3 + B3 polycondensation: thermal, mechanical, anti-corrosive and antimicrobial properties of poly (urethane-urea)

et al. 2014

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First Shell Substitution Effects in Hyperbranched Polymers: Kinetic−Recursive Probability Analysis

Cited by 9 publications

References 58 publications

Study of negative substitution and monomer self‐condensation effects on molar mass and structural characteristics of hyperbranched polyesters originating from a high‐functionality core

Study of negative substitution and monomer self‐condensation effects on molar mass and structural characteristics of hyperbranched polyesters originating from a high‐functionality core

Relationship between structure and aromatic solvent permeability of crosslinked polyurethanes based on hyperbranched polyesters

Nitrogen rich hyperbranched polyol via A3 + B3 polycondensation: thermal, mechanical, anti-corrosive and antimicrobial properties of poly (urethane-urea)

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