scholarly journals Adhesive Resins with High Shelf-Life Stability Based on Tetra Unsaturated Monomers with Tertiary Amines Moieties

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1944
Author(s):  
Alma Antonia Pérez-Mondragón ◽  
Carlos Enrique Cuevas-Suárez ◽  
Jesús García-Serrano ◽  
Nayely Trejo-Carbajal ◽  
A. Lobo-Guerrero ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Double Bond ◽  
Shelf Life ◽  
Polymerization Rate ◽  
Tertiary Amines ◽  
Adhesive Systems ◽  
Double Bond Conversion ◽  
Initiator System ◽  
Ft Ir ◽  
Shelf Life Stability

This work reports the use of two monomers with two tertiary amines and four methacrylic (TTME) or acrylic (TTAC) terminal groups as co-initiators in the formulation of experimental resin adhesive systems. Both monomers were characterized by FT-IR and 1H NMR spectroscopies. The control adhesive was formulated with BisGMA, TEGDMA, HEMA, and the binary system CQ-EDAB as a photo-initiator system. For the experimental adhesives, the EDAB was completely replaced for the TTME or the TTAC monomers. The adhesives formulated with TTME or TTAC monomers achieved double bond conversion values close to 75%. Regarding the polymerization rate, materials formulated with TTME or TTAC achieved lower values than the material formulated with EDAB, giving them high shelf-life stability. The degree of conversion after shelf simulation was only reduced for the EDAB material. Ultimate tensile strength, translucency parameter, and micro-tensile bond strength to dentin were similar for control and experimental adhesive resins. Due to their characteristics, TTME and TTAC monomers are potentially useful in the formulation of photopolymerizable resins for dental use with high shelf-life stability.

Synthesis and Evaluation of Bifunctional Monomers Derived from Post-Industrial PET as Crosslinking Agents for Acrylic Monomers

2014 ◽  
Vol 976 ◽  
pp. 59-63
Author(s):  
Antonio Cruz-Aguilar ◽  
Juan Coreño-Alonso ◽  
Ana María Herrera González
Keyword(s):  
Double Bond ◽  
Acryloyl Chloride ◽  
Thermal Stabilities ◽  
Pet Waste ◽  
Acrylic Monomers ◽  
Double Bond Conversion ◽  
Bifunctional Monomer ◽  
Ft Ir ◽  
Post Industrial ◽  
Crosslinking Agents

Two bifunctional monomers, bis (acryloxyethyl) terephthalate (BAOET) and bis (allyloxycarboniloxyethyl) terephthalate (BAOCOET), derived from PET waste were tested as crosslinking agents for acrylic and methacrylic acids (AA and MA, respectively). BAOET and BAOCOET were obtained from the reactions of acryloyl chloride and allyl chloroformate, respectively, with bis (hydroxyethyl) terephthalate (BHET). This was obtained from the glycolysis of postindustrial PET with ethyleneglycol (EG). Both bifunctional monomers were characterized by NMR 1H. Polymerizations of BAOET and BAOCOET with the acrylic monomers were performed using bifunctional monomer to acrylic monomer weight ratios of 1:10, 1:2 and 1:1, for each of the four combinations, using 2 wt % of benzoyl peroxide (BPO) as thermal initiator. The obtained gel proportions of the crosslinked polymers were above 90% for most of the cases, requiring times from 10 to 60 min. For all of the experiments, complete double bond conversion was observed by FT-IR. Polymers showed thermal stabilities higher than 200°C.

scholarly journals Depth-Related Curing Potential of Ormocer- and Dimethacrylate-Based Bulk-Fill Composites

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6753
Author(s):  
Ramona S. Oltramare ◽  
Reto Odermatt ◽  
Phoebe Burrer ◽  
Thomas Attin ◽  
Tobias T. Tauböck
Keyword(s):  
Double Bond ◽  
Repeated Measures ◽  
In Vitro Study ◽  
High Viscosity ◽  
Degree Of Conversion ◽  
Double Bond Conversion ◽  
Nanohybrid Composite ◽  
Post Hoc ◽  
One Way Anova

The aim of this in vitro study was to investigate the degree of C=C double bond conversion of high-viscosity dimethacrylate- or ormocer-based bulk-fill composites as a function of measurement depth. Four bulk-fill composites (Tetric EvoCeram Bulk Fill, x-tra fil, SonicFill, and Bulk Ormocer) and the conventional nanohybrid composite Tetric EvoCeram were applied in standardized Class II cavities (n = 6 per group) and photoactivated for 20 s at 1350 mW/cm2. The degree of conversion of the composites was assessed using Fourier-transform infrared spectroscopy at seven measurement depths (0.15, 1, 2, 3, 4, 5, 6 mm). Data were analyzed using repeated measures ANOVA and one-way ANOVA with Bonferroni post-hoc tests (α = 0.05). The investigated bulk-fill composites showed at least 80% of their maximum degree of conversion (80% DCmax) up to a measuring depth of at least 4 mm. Tetric EvoCeram Bulk Fill and Bulk Ormocer achieved more than 80% DCmax up to a measuring depth of 5 mm, x-tra fil up to 6 mm. The conventional nanohybrid composite Tetric EvoCeram achieved more than 80% DCmax up to 3 mm. In contrast to the conventional composite, the investigated ormocer- and dimethacrylate-based bulk-fill composites can be photo-polymerized in thick layers of up to at least 4 mm with regard to their degree of C=C double bond conversion.

scholarly journals THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Tensile Strength ◽  
Physicochemical Characterization ◽  
Face Mask ◽  
Physicochemical Characteristics ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Ft Ir ◽  
The Government ◽  
Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

scholarly journals Antibacterial Properties of Biofilm Schiff Base Derived from Dialdehyde Cellulose and Chitosan

2019 ◽  
Vol 19 (2) ◽  
pp. 405
Author(s):  
Agung Pratama ◽  
Firman Sebayang ◽  
Rumondang Bulan Nasution
Keyword(s):  
Tensile Strength ◽  
Antibacterial Activity ◽  
Schiff Base ◽  
Antibacterial Properties ◽  
Oxidized Cellulose ◽  
Natural Polymers ◽  
Dialdehyde Cellulose ◽  
Ft Ir ◽  
Ir Analysis

Cellulose and chitosan are natural polymers that have been used as biocomposite. The aim of this research is to obtain biofilms from chitosan and oxidized cellulose crosslinks. This research is divided into three steps, i.e., isolation of cellulose from oil palm trunk and oxidation of cellulose using NaIO4 (0.2; 0.4; 0.6; 0.8; 1.0 mg/mL) to obtain dialdehyde cellulose (DAC), crosslink of oxidized cellulose with chitosan (DD = 72.85%) to obtain biofilm of chitosan/DAC (CDAC), and characterization of biofilms. The crosslinked reaction was confirmed by FT-IR analysis that showed the spectrum of Schiff base C=N group at 1651 cm–1. Tensile strength increased gradually when the NaIO4 concentration used was 0.2–0.6 mg/mL, but after those concentrations, the tensile strength slightly decreased. The morphology analysis showed that CDAC had smoother morphology than DAC, which was shown rough and showed some particle indicated the presence of unreacted cellulose. CDAC biofilms that prepared with 1.0 mg/mL NaIO4 showed the greatest antibacterial activity.

Pentacarbonyl(aminocarbene)chromium(0) Complexes : Reductive Cleavage of the Chromium-Carbon Double Bond to Secondary and Tertiary Amines

Synlett ◽  
1994 ◽  
Vol 1994 (08) ◽  
pp. 677-678 ◽  
Author(s):  
C. Baldoli ◽  
P. Del Buttero ◽  
E. Licandro ◽  
S. Maiorana ◽  
A. Papagni ◽  
...  
Keyword(s):  
Double Bond ◽  
Reductive Cleavage ◽  
Tertiary Amines ◽  
Carbon Double Bond

Copolymerization of ethylene and 4-vinylcyclohexene by various metallocenes in the presence of Al(iBu)3/[Ph3C][B(C6F5)4]

e-Polymers ◽  
2001 ◽  
Vol 1 (1) ◽  
Author(s):  
Il Kim ◽  
Young-tae Kim
Keyword(s):  
Double Bond ◽  
Intrinsic Viscosity ◽  
Polymerization Rate ◽  
Viscosity Measurements

AbstractCopolymerizations of ethylene and 4-vinylcyclohexene (VCH) were carried out with isospecific rac-1,2-ethylenebis(1-indenyl)Zr(N(CH3)2)2 [rac-(EBI)Zr(NMe2)2] and syndiospecific isopropylidene(cyclopentadienyl)(9- fluorenyl)ZrMe2 [iPr(Cp)(Flu)ZrMe2] compounds combined with Al(iBu)3/ [Ph3C][B(C6F5)4] as a cocatalyst system. VCH was regioselectively inserted into the copolymer through the vinyl double bond, leaving the endocyclic double bond unreacted. rac-(EBI)Zr(NMe2)2 catalyst showed a higher polymerization rate but lower VCH reactivity than the iPr(Cp)(Flu)ZrMe2 catalyst. The calculation of copolymerization parameters according to Kelen-Tüdös resulted in rE = 131.49 and rVCH = 0.02 for the iPr(Cp)(Flu)ZrMe2 catalyst. When [VCH] in feed was 90.5 mol-%, [VCH] in polymer was 1.88 and 8.04 mol-% for rac-(EBI)Zr(NMe2)2 and iPr(Cp)(Flu)ZrMe2 catalysts, respectively. The resulting copolymers were characterized using NMR, Raman and intrinsic viscosity measurements.

Analysis of Double Bond Conversion of Photopolymerizable Monomers by FTIR-ATR Spectroscopy

2019 ◽  
Vol 96 (8) ◽  
pp. 1786-1789 ◽  
Author(s):  
Ana M. Herrera-González ◽  
Martín Caldera-Villalobos ◽  
Alma A. Pérez-Mondragón ◽  
Carlos E. Cuevas-Suárez ◽  
J. Abraham González-López
Keyword(s):  
Double Bond ◽  
Double Bond Conversion ◽  
Atr Spectroscopy
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