scholarly journals Addition of Graphene Oxide in Different Stages of the Synthesis of Waterborne Polyurethane-Urea Adhesives and Its Influence on Their Structure, Thermal, Viscoelastic and Adhesion Properties

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2899 ◽  
Author(s):  
Abir Tounici ◽  
José Miguel Martín-Martínez
Keyword(s):  
Graphene Oxide ◽  
Waterborne Polyurethane ◽  
Peel Strength ◽  
Lower Percentage ◽  
Gravimetric Analysis ◽  
Water Addition ◽  
Covalent Bonds ◽  
Adhesion Properties ◽  
Lap Shear ◽  
Before And After

In this study, 0.04 wt % graphene oxide (GO) was added in different stages (before and after prepolymer formation, and during water addition) of the synthesis of waterborne polyurethane-urea dispersions (PUDs) prepared by using the acetone method. The structural, thermal, mechanical, viscoelastic, surface and adhesion properties of the polyurethane-ureas (PUUs) containing 0.04 wt % GO were studied. The addition of GO before and after prepolymer formation produced covalent bonds between the GO sheets and the NCO groups of the isocyanate, whereas the GO sheets were trapped between the polyurethane chains when added during water addition step. As a consequence, depending on the stage of the PUD synthesis in which GO was added, the degree of micro-phase separation between the hard and soft segments changed differently. The addition of GO before prepolymer formation changed more efficiently the polyurethane-urea structure, i.e., the covalently bonded GO sheets disturbed the interactions between the hard segments causing lower percentage of free urethane groups, higher crystallinity, lower storage modulus, higher yield stress and T-peel strength. The interactions between the GO sheets and the polymeric chains have been evidenced by plate-plate rheology, thermal gravimetric analysis and spectroscopy. On the other hand, physical interactions between GO and the polyurethane-urea chains were produced when GO was added in water during the synthesis, i.e., GO was acting as a nanofiller, which justified the improved mechanical properties and high lap-shear strength, but poor T-peel strength.

scholarly journals Synthesis and Characterization of Polyesteramide Hot Melt Adhesive from Low Purity Dimer Acid, Ethylenediamine, and Ethanolamine

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Pravin G. Kadam ◽  
Parth Vaidya ◽  
Shashank T. Mhaske
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Acid Value ◽  
Peel Strength ◽  
Partial Replacement ◽  
Adhesion Properties ◽  
Dimer Acid ◽  
Lap Shear ◽  
Hot Melt

Polyesteramide hot melt adhesive (HMA) was synthesized using low purity dimer acid (composition: 3% linoleic acid, 75% dimer acid, and 22% trimer acid), ethanolamine, and ethylenediamine. Ethanolamine was added as a partial replacement (10, 20, and 30%) of ethylenediamine. Prepared HMAs were characterized for acid value, amine value, hydroxyl value, Fourier transform infrared spectroscopy, mechanical (tensile strength, percentage strain at brea, and shore D hardness), thermal (glass transition temperature, melting temperature, enthalpy of melting, crystallization temperature, and enthalpy of crystallization), rheological (viscosity versus shear rate and viscosity versus time), and adhesion properties (T-peel strength and lap shear strength). Replacement of ethylenediamine by ethanolamine replaced certain amide linkages by ester linkages, decreasing the intermolecular hydrogen bonding, leading to decrease in the crystallinity of the material, and thus the mechanical, thermal, adhesion, and rheological properties. However, HMAs prepared using ethanolamine will have better low temperature flexibility due to low glass transition temperature and better adhesion process due to the lower viscosity.

scholarly journals New Waterborne Polyurethane-Urea Synthesized with Ether-Carbonate Copolymer and Amino-Alcohol Chain Extenders with Tailored Pressure-Sensitive Adhesion Properties

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 627 ◽  
Author(s):  
Mónica Fuensanta ◽  
Abbas Khoshnood ◽  
Francisco Rodríguez-Llansola ◽  
José Miguel Martín-Martínez
Keyword(s):  
Amino Alcohol ◽  
Peel Test ◽  
Waterborne Polyurethane ◽  
Chain Extender ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Oh Groups ◽  
Pressure Sensitive ◽  
Chain Extenders

New waterborne polyurethane-urea dispersions with adequate adhesion and cohesion properties have been synthesized by reacting isophorone diisocyanate, copolymer of ether and carbonate diol polyol and three amino-alcohols with different number of OH groups chain extenders using the prepolymer method. The waterborne polyurethane-urea dispersions were characterized by pH, particle-size distribution, and viscosity, and the polyurethane-urea films were characterized by attenuated total reflectance infrared (ATR-IR) spectroscopy, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and plate-plate rheology (temperature and frequency sweeps). Polyurethane-urea pressure-sensitive adhesives (PUU PSAs) were prepared by placing the waterborne polyurethane dispersions on polyethylene terephthalate (PET) films and they were characterized at 25 °C by creep test, tack and 180° peel test. The waterborne polyurethane-urea dispersions showed mean particle sizes between 51 and 78 nm and viscosities in the range of 58–133 mPa·s. The polyurethane-urea films showed glass transition temperatures (Tgs) lower than −64 °C, and they showed a cross of the storage and loss moduli between −8 and 68 °C depending on the number of OH groups in the amino-alcohol chain extender. Different types of PUU PSAs (removable, high shear) were obtained by changing the number of OH groups in the amino-alcohol chain extender. The tack at 25 °C of the PUU PSAs varied between 488 and 1807 kPa and the 180° peel strength values ranged between 0.4 and 6.4 N/cm, and their holding times were between 2 min and 5 days. The new PUU PSAs made with amino-alcohol chain extender seemed very promising for designing environmentally friendly waterborne PSAs with high tack and improved cohesion and adhesion property.

scholarly journals Structure and adhesion properties before and after hydrolytic ageing of polyurethane urea adhesives made with mixtures of waterborne polyurethane dispersions

2018 ◽  
Vol 85 ◽  
pp. 165-176 ◽  
Author(s):  
Mónica Fuensanta ◽  
José Antonio Jofre-Reche ◽  
Francisco Rodríguez-Llansola ◽  
Víctor Costa ◽  
José Miguel Martín-Martínez
Keyword(s):  
Waterborne Polyurethane ◽  
Adhesion Properties ◽  
Before And After ◽  
Polyurethane Dispersions

scholarly journals Copolymerization of Styrene and Pentadecylphenylmethacrylate (PDPMA): Synthesis, Characterization, Thermomechanical and Adhesion Properties

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 97
Author(s):  
Tomy Muringayil Joseph ◽  
Sumi Murali Nair ◽  
Suresh Kattimuttathu Ittara ◽  
Józef T. Haponiuk ◽  
Sabu Thomas
Keyword(s):  
Gel Permeation Chromatography ◽  
Complex Viscosity ◽  
Peel Strength ◽  
Morphological Characterization ◽  
Reactivity Ratio ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Lap Shear ◽  
Hard Shell ◽  
Styrene Content

The copolymerization of styrene (St) with a bioderived monomer, pentadecylphenyl methacrylate (PDPMA), via atom transfer radical polymerization (ATRP) was studied in this work. The copolymerization reactivity ratio was calculated using the composition data obtained from 1H NMR spectroscopy, applying Kelen-Tudos and Finemann-Ross methods. The reactivity ratio of styrene (r1 = 0.93) and PDPMA (r2 = 0.05) suggested random copolymerization of the two monomers with alternation. The copolymerization conversion increased with increasing PDPMA concentration of the feed, upto 70 wt % PDPMA, but decreased thereafter. The molecular weight determined by gel permeation chromatography was lower than the theoretical values and the polydispersity increased from 1.32 to 2.19, with increasing PDPMA content in the feed. The influence of styrene content on the glass transition and thermal decomposition behavior of the copolymers was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis, respectively. Morphological characterization by transmission electron microscopy (TEM) revealed a phase separated soft core-hard shell type structure. The complex viscosity and adhesion properties like peel strength and lap shear strength of the copolymer on different substrates increased with increasing styrene content.

scholarly journals Effect of Carbon Black Nanofiller on Adhesion Properties of SBS Rubber Surfaces Treated by Low-Pressure Plasma

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 616
Author(s):  
Jacek Tyczkowski ◽  
Jacek Balcerzak ◽  
Jan Sielski ◽  
Iwona Krawczyk-Kłys
Keyword(s):  
Carbon Black ◽  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
Peel Test ◽  
Low Pressure ◽  
Peel Strength ◽  
Bonded Joints ◽  
Adhesion Properties ◽  
Before And After ◽  
Adhesive Bonded Joints

Studies on the surface modification of commercial styrene-butadiene-styrene (SBS) rubber with different carbon black (CB) nanofiller content (10–80 parts per hundred parts of rubber (phr)) performed by low-pressure oxygen plasma are presented in this paper. The adhesion properties of the rubber were determined by the peel test for adhesive-bonded joints prepared with a water-based polyurethane (PU) adhesive. The chemical structure and morphology of the SBS rubber surface before and after plasma treatment were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The peel tests showed that the plasma treatment significantly improved the strength of adhesive-bonded joints in the entire range of CB tested, revealing a clear maximum for approximately 50 phr of CB. It was also found that as a result of plasma treatment, functional groups that are responsible for the reactions with the PU adhesive, such as C−OH and C=O, were formed, and their concentration, similar to the peel strength, showed maximum values for approximately 50 phr CB. The occurrence of these maxima was explained using the bound rubber model.

scholarly journals Effect of Nitrogen-Doped Graphene Oxide on the Aging Behavior of Nitrile–Butadiene Rubber

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1637 ◽  
Author(s):  
Songbo Chen ◽  
Tianxiang Li ◽  
Songhan Wan ◽  
Xing Huang ◽  
Shuwei Cai ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Butadiene Rubber ◽  
Aging Behavior ◽  
Covalent Bonds ◽  
Nitrogen Doped ◽  
Nitrile Butadiene Rubber ◽  
Equilibrium Swelling ◽  
Before And After ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Nitrogen-doped graphene oxide (GO), namely, NG, was prepared by o-phenylenediamine (OPD) grafting onto GO. The structure and morphology of NG were characterized by FITR, XRD, SEM, EDS, Raman spectroscopy, and TGA. OPD was linked to the GO surface by covalent bonds, and the absorption peak of the C=N bond in the phenazine structure was identified in the FITR spectra. The aging resistance properties of nitrile-butadiene rubber (NBR)-NG composites was investigated by mechanical testing, before and after aging. The resistance of the NBR/NG composites with the addition of 3 phr NG fillers was the highest. The aging mechanism was investigated by TGA-DSC, DMA, equilibrium swelling testing, and ATR-FTIR. The results showed that NG could effectively inhibit chain cross-linking in NBR.

EFEKTIVITAS MODEL PEMBELAJARAN KOOPERATIF TIPE TEAMS GAMES TOURNAMENT (TGT) BERBANTUAN MEDIA KARTU SOAL PADA SUB MATERI IKATAN KOVALEN KELAS X MIA DI SMA ISLAM HARUNIYAH PONTIANAK

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Zulfadhli Abdillah
Keyword(s):  
Student Learning ◽  
Learning Outcomes ◽  
Covalent Bond ◽  
Student Learning Outcomes ◽  
Learning Model ◽  
Covalent Bonds ◽  
Team Games ◽  
Bonding Material ◽  
Before And After ◽  
Tenth Grade

 This  study  is  motivated  by  the  low  learning  outcomes  in  the  Sub-covalent  Bond class of tenth-grade students, SMA Islam Haruniyah Pontianak. This problem is due to the  lack  of  students'  understanding  of  the  concept  of  Covalent  Bonds.  Therefore,  a proper learning model is required to improve students’ understanding of Covalent Bond concepts  based  on  the  characteristics  of  both  learning  materials    and  students.  This study  aimed  to  investigate  the  differences  in  the  student  learning  outcomes  and  the effectiveness of the question card-based on TGT learning in the Sub-covalent Bonding material. Using the pre-experimental method of one-group pretest-posttest design, the tenth-grade  students  of  Math  and  Science  Class  of  SMS  Islam  Haruniyah  Pontianak participated in this study. The data collection tools used were learning outcomes tests, observation sheets, and interview sheets. The results of data analysis revealed that the average  pretest  score  was  36  and  the  posttest  was  62.94.  In  addition,  the  t-test statistical  analysis  indicated  a  significance  value  of  0.00  (0.00  <0.05)  which  meanth that there were differences in student learning outcomes between before and after the question  card-based  TGT  learning  model  implemented.  The  gain  value  was  0.42.  In other words, the  question card-based on TGT learning model is effective in improving the student  learning outcomes with good category. Keywords: Covalent Bond, Question Card, Team Games Tournament (TGT)

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