Molecular weight development in the superacid-catalyzed polyhydroxyalkylation of 1-propylisatin and biphenyl at stoichiometric conditions

Cruz‐Rosado, Alfredo; Romero‐Hernández, Juan Enrique; Ríos‐López, Marlene; López-Morales, Salvador; Cedillo, Gerardo; Ríos-Ruiz, Lucero Mayra; Cetina-Mancilla, Enoc; Palacios‐Alquisira, Joaquín; Zolotukhin, Mikhail G.; Vivaldo‐Lima, Eduardo

doi:10.1016/j.polymer.2022.124616

Cited by 6 publications

(10 citation statements)

References 63 publications

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“…According to “Flory’s principle”, k ab = k am = k bm = k mm . Although the cases where these rate constants were not equal were reported lately in some specific SGPs, − the rate constant difference is negligible in the majority of SGPs. The P i values are all of the same and equal to 1 in conventional SGPs, while they decrease with the increase of the length of the species when the SGPs take place exclusively in confined nanochannels similar to our previous work .…”

Section: Resultsmentioning

confidence: 96%

Synthesis of Narrowly Distributed α,ω-Bifunctionalized Conjugated Polymers

et al. 2023

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End-functional conjugated polymers are generally synthesized with stoichiometric-biased monomer combinations in conventional step growth polymerizations (SGPs), which lead to broad species distribution and difficult-to-control end functionality of the polymeric products due to the uncontrolled nature of the method employed. To overcome such disadvantages, a general controlled method was developed for the synthesis of narrowly distributed end-functional conjugated polymers with high-end functionality purity and a predefined molecular weight. This strategy relies on the spatial confinement effect of the nanoreactors, whereby polymeric species with higher molecular weight have a lower chance of further involvement in SGP. Numerical calculations on the kinetic equations demonstrated the formation of narrowly distributed polymers with a high degree of chain-end functionalization. Experimental results based on various analysis methods confirmed the controlled synthesis of bifunctionalized poly(p-phenylene)s with high-end functionality purity and low dispersity value down to 1.06.

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Section: Resultsmentioning

confidence: 96%

Synthesis of Narrowly Distributed α,ω-Bifunctionalized Conjugated Polymers

et al. 2023

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“…As explained in the introduction, the stoichiometric (SC) and excess of A 2 monomer cases were studied earlier. 32 The absence of NSE when A 2 was in excess motivated the present study. As shown in Scheme 2 and Table 1, we used three values of the stoichiometric imbalance ratio (SIR), r, which is defined in equation (1).…”

Section: Synthesis and Gpc Characterization Of Polymers In Excess Of ...mentioning

confidence: 83%

“…33 As explained earlier, the superacid-catalyzed polyhydroxyalkylation of 1-propyl isatin and biphenyl proceeds in two regions of very different molecular weights (HMWR and LMWR), regardless of the value of the stoichiometric imbalance ratio (parameter r). These two regions were observed at stoichiometric conditions (r = 1), in excess of A 2 (r > 1), 32 and also in excess of B 2 (r < 1) (Figure 2). An increasing trend of M w which leads to a strong NSE is clearly observed in Figure 3, which shows molecular weight development in the HMWR.…”

Section: Synthesis and Gpc Characterization Of Polymers In Excess Of ...mentioning

confidence: 93%

“…It was known that there are four types of polymer molecules: A, B, M, and C, and these types of polymer molecules are present in each region, HMWR and LMWR. 32 Using a methodology documented in the literature, 34,35 the chemical structures were assigned to the MALDI-TOF signals of the spectra obtained. Figure 8(a) shows an example of the assignment of signals from MALDI-TOF to different types of polymer molecules (symbols explained in Figure 8(b)).…”

Section: Synthesis and Gpc Characterization Of Polymers In Excess Of ...mentioning

confidence: 99%

“…31 A carefully planned experimental kinetic study on the superacid catalyzed polyhydroxyalkylation of biphenyl (monomer A 2 ) and 1-propyl isatin (monomer B 2 ), at stoichiometric conditions, using trifluoromethanesulfonic acid (TFSA) as the catalyst, was carried out. 32 Evolution of molecular weight distributions measured by gel permeation chromatography (GPC) and matrix-assisted laser-desorption/ionization-time-of-flight (MALDI-TOF) showed that although linear polymer formation dominates the polymerization, there was significant cyclization taking place. They also showed that there were two polymer populations in the reaction system.…”

Section: Introductionmentioning

confidence: 99%

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Non-stoichiometric effect in the superacid-catalyzed polyhydroxyalkylation of biphenyl and 1-propyl isatin

Cruz‐Rosado

Romero‐Hernández

Ríos‐López

et al. 2023

High Performance Polymers

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An experimental study on the superacid-catalyzed polyhydroxyalkylation of biphenyl (A2 monomer) and 1-propyl isatin (B2 monomer) at non-stoichiometric conditions is presented. The produced high-performance polymers were characterized by gel permeation chromatography matrix-assisted laser-desorption/ionization-time-of-flight (MALDI-TOF), nuclear magnetic resonance and diffusion-ordered spectroscopy (DOSY). High molecular weights (Mw > 150,000 Da) and ultra-high molecular weights (Mw ∼ 900,000 Da) are obtained when B2 is used in excess, which agrees with the behavior observed at non-stoichiometric conditions for other superacid catalyzed polyhydroxyalkylations, contrary to the case when A2 is used in excess, where a reduction in molecular weight is obtained, as reported in a previous study from our group. A, B, and M types of linear polymer molecules, as well as C-type cycles, were observed from the MALDI-TOF data.

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