Effect of reaction time on the molecular weight distribution of polyurethane modified epoxy and its properties

Triwulandari, Evi; Fatriasari, Widya; Iswanto, Apri Heri; Septiyanti, Melati; Umam, Eko Fahrul; Ghozali, Muhammad

doi:10.1016/j.jmrt.2022.05.185

Cited by 8 publications

(6 citation statements)

References 36 publications

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“…NaOH was used in the synthesis of the resin, − and the epoxy equivalent weight (EEW) was measured using Section . After the ring of the curcumin epoxy was opened using hydrochloric acid, NaOH was slowly added to change the C–Cl bond to C–OH.…”

Section: Resultsmentioning

confidence: 99%

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Jeong,

Ju,

Hong

et al. 2024

ACS Omega

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We synthesized a novel curcumin-based bioepoxy resin by introducing epichlorohydrin (ECH) into the hydroxyl groups of curcumin and analyzed it using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The epoxy equivalent weight (EEW) was determined based on a reaction with sodium hydroxide (NaOH) through titration, and the actual curing process was conducted after exploring the optimal conditions using an amine-based curing agent through dynamic scanning in differential scanning calorimetry (DSC) and isotherm analysis. The cured epoxy resin had a tensile strength, Young's modulus, and glass transition temperature (T g ) of 33 MPa, 1.4 GPa, and 86 °C, respectively. Interestingly, the diunsaturated ketone contained in the epoxy resin showed on-demand chemical cleavability, in that it had been decomposed into an aldehyde and ketone only after having been converted to a hydroxyl ketone through an oxidation reaction. The results of this study can significantly contribute to improving the eco-friendliness and recyclability of epoxy resins used in fields requiring long-term stability and chemical resistance.

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Section: Resultsmentioning

confidence: 99%

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Jeong,

Ju,

Hong

et al. 2024

ACS Omega

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“…The pre‐polymerization stage was 3 h, and the condensation stage was 3 h. After the pre‐polymerization stage, the samples were withdrawn and analyzed, following the samples withdrawn every other hour. The molecular weight and distribution of PCDL in different reaction time were discussed [23] . Three parallel experiments were carried out.…”

Section: Resultsmentioning

confidence: 99%

“…The molecular weight and distribution of PCDL in different reaction time were discussed. [23] Three parallel experiments were carried out. In Figure 4d, with the increase of vacuum degree, the by-products phenol and tetrahydrofuran with low boiling point were extracted, and the molecular weight of the polymer increased continuously.…”

Section: Resultsmentioning

confidence: 99%

Efficient Transesterification Preparation of Polycarbonate Diol with High Molecular Weight Using TiO₂/SiO₂ Solid Acid Catalysts

Chong

Qian²,

Wei

et al. 2023

ChemistrySelect

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A series of TiO2/SiO2 catalysts were prepared by hydrolysis and used in the transesterification of diphenyl carbonate (DPC) and 1,4‐butanediol (BDO) to produce polycarbonate diol (PCDL). The physical properties of TiO2/SiO2 solid acid catalysts were characterized, and the relationship between their structural features and catalytic transesterification reaction was analyzed. The effects of various reaction conditions such as hydrolysis procedure, transesterification temperature, catalyst amount, and the mole ratio of the starting materials on the catalytic synthesis of PCDL were investigated. The maximum catalytic activity was based on the TiO2 : SiO2=3 : 1 with hydrolysis procedure of adding the Ti/Si mixture (A) to deionized water and anhydrous ethanol (B). The as‐synthesized TiO2/SiO2‐A‐to‐B catalyst exhibits rough surface with the average pore size of 6.75 nm, and the total acid amount of 1.07 mmol/g. The PCDL yield of transesterification reached 89.8 %, and the number average molecular weight reached 9074 g/mol under the optimal reaction conditions, and the molecular weight of the PCDL product could be adjusted.

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“…The average molecular weight of OBCs was determined according to the method of Triwulandari by using a gel chromatograph (Waters, 2414, USA) equipped with a Shodex SB‐806MHQ column. [ 46 ] The OBC was dissolved in 0.1 m NaCl solution and then filtered using a 0.2 µm filter membrane. The calibration was carried out using polyethylene glycol with degree of polymerization of 200, 400, and 600 as the standard.…”

Section: Methodsmentioning

confidence: 99%

Antibacterial Activity and Mechanism of Oxidized Bacterial Nanocellulose with Different Carboxyl Content

Tian

Chen

et al. 2023

Macromolecular Bioscience

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Oxidized bacterial nanocellulose (OBC) is reported to prevent microbial growth, but its antibacterial characteristics and mechanism are still unclear.Here, the antibacterial mechanism of OBC is explored by detecting and assessing the interaction of OBC with different carboxyl content on Staphylococcus aureus and Escherichia coli. The results show that OBC has strong antibacterial activity and antibiofilm activity against S. aureus and E. coli, which is positively correlated with the carboxyl content of OBC. After OBC treatment, the bacteria adhesion is inhibited and the cell membrane is destroyed leading to increased permeability. Further investigation reveals that the concentration of cyclic diguanosine monophosphate (c-di-GMP) that induced biofilm formation is significantly decreased to 1.81 pmol mg −1 after OBC treatment. In addition, OBC inactivates mature biofilms, with inactivation rates up to 79.3%. This study suggests that OBC has excellent antibacterial and antiadhesion properties, which can increase the cell membrane permeability and inhibit c-di-GMP formation. In addition, OBC also has a strong inactivation effect on mature biofilm, which can be used as an effective antibiofilm agent.

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Effect of reaction time on the molecular weight distribution of polyurethane modified epoxy and its properties

Cited by 8 publications

References 36 publications

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Efficient Transesterification Preparation of Polycarbonate Diol with High Molecular Weight Using TiO₂/SiO₂ Solid Acid Catalysts

Antibacterial Activity and Mechanism of Oxidized Bacterial Nanocellulose with Different Carboxyl Content

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Effect of reaction time on the molecular weight distribution of polyurethane modified epoxy and its properties

Cited by 8 publications

References 36 publications

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability

Efficient Transesterification Preparation of Polycarbonate Diol with High Molecular Weight Using TiO2/SiO2 Solid Acid Catalysts

Antibacterial Activity and Mechanism of Oxidized Bacterial Nanocellulose with Different Carboxyl Content

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Product

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About

Efficient Transesterification Preparation of Polycarbonate Diol with High Molecular Weight Using TiO₂/SiO₂ Solid Acid Catalysts