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.

Synthesis and characterization of novel methacrylate copolymers having pendant piperonyl group: monomer reactivity ratio, thermal degradation kinetics, and biological activity

2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1432-S1445
Author(s):  
Ibrahim Erol ◽  
Bayram Gencer ◽  
Zeki Gurler
Keyword(s):  
Biological Activity ◽  
Degradation Kinetics ◽  
Gel Permeation Chromatography ◽  
Reactivity Ratio ◽  
Thermal Degradation Kinetics ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Monomer Reactivity Ratio ◽  
Bacteria And Fungi ◽  
Photo Stability

In this study, 2-{[(2H-1,3-benzodioxol-5-yl)methyl]amino}-2-oxoethyl 2-methylprop-2-enoate (BMAOME) monomer was synthesized, and copolymers were prepared with glycidyl methacrylate (GMA). Structural characterizations of the compounds were performed using FTIR, 1H-, and 13C-NMR techniques. Monomer reactivity ratio values were calculated by Finemann–Ross (FR) and Kelen–Tudos (KT) methods. The Tg value of the polymers was determined by differential scanning calorimetry (DSC) and their thermal stability was determined by thermogravimetric analysis (TGA). The molecular weights (w and n) and polydispersity index of the polymers were determined by gel permeation chromatography. The Ea value of thermal decomposition was determined by using the Ozawa and Kissinger methods. The photo-stability of the copolymers was investigated. Furthermore, the photo-stability of the copolymers and the biological activity of polymers against different types of bacteria and fungi were investigated.

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 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.

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO2 as Blowing Agent

2017 ◽  
Vol 36 (4) ◽  
pp. 167-182 ◽  
Author(s):  
Hongfu Zhou ◽  
Zhanjia Wang ◽  
Guozhi Xu ◽  
Xiangdong Wang ◽  
Bianying Wen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Density Polyethylene ◽  
Crosslinking Agent ◽  
Volume Ratio ◽  
Gel Permeation Chromatography ◽  
Complex Viscosity ◽  
High Density ◽  
Foaming Properties ◽  
Scanning Calorimetry ◽  
Blowing Agent

Different content of dicumyl peroxide (DCP) acting as a crosslinking agent was mixed with high-density polyethylene (HDPE) in a Haake internal mixer to improve the viscoelasticity and foamability of HDPE. The crosslinked HDPE samples were foamed in a high pressure stainless steel autoclave using CO2 as the physical blowing agent. The molecular weight, crystallization behavior and rheological properties of various HDPE samples were examined by gel permeation chromatography, differential scanning calorimetry, rotational rheometer, and torque rheometer, respectively. The foaming properties of various samples were characterized by scanning electron microscope and densimeter. It was found that with the increasing content of DCP, the molecular weight, crystallization temperature, complex viscosity, and storage modulus of HDPE increased and the crystallization degree of HDPE decreased. When 0.2 phr of DCP was introduced into HDPE, the expansion volume ratio of HDPE showed the highest value, which could be more than 7 times.

New Polyurethane Sealants Containing Rosin for Non-Invasive Disc Regeneration Surgery

2013 ◽  
Vol 583 ◽  
pp. 67-79 ◽  
Author(s):  
Pilar Carbonell-Blasco ◽  
Iulian Antoniac ◽  
Jose Miguel Martin-Martinez
Keyword(s):  
Peel Test ◽  
Peel Strength ◽  
Chain Extender ◽  
Polymer Chains ◽  
Scanning Calorimetry ◽  
Disc Regeneration ◽  
Non Invasive ◽  
Lap Shear ◽  
Chain Extenders ◽  
Butane Diol

Different polyurethane sealants were prepared by reacting methylene dyísocyanate and polyadipate of 1,4 butane diol (Mw : 2500 daltons) by using the prepolymer method and different mixtures of rosin and 1,4 butane diol were used as chain extenders. The polyurethanes were characterized by plate-plate rheology, molecular weight distribution, Differential Scanning Calorimetry (DSC), and Laser Confocal Microscopy. The tack of the polyurethanes sealants was obtained by using a modified probe tack method, and their adhesion was obtained by T-peel test of leather/polyurethane sealant/leather joints and by single lap-shear tests of aluminium/polyurethane sealant/aluminium joints. Depending on the rosin content in the chain extender the structure of the polyurethanes was different, i.e. more urethane and urethane-amide hard segments were created up to 50 eq% rosin in the chain extender, and separation of domains was prevailing in the polyurethanes with higher rosin content. Furthermore, the addition of rosin caused an increase in the length of the polymer chains and in the storage modulus (particularly in the polyurethane containing 50 eq% rosin), and decrease in the melting enthalpy. Moreover, the crystallinity of the polyurethanes containing up to 50 eq% rosin showed lower number and smaller spherulites, Finally, the tack at 37 °C and the peel strength increased in the joints made with the polyurethane sealants containing rosin whereas the adhesive shear strength decreased when the polyurethane sealant contained 50 eq% rosin or less.

scholarly journals Preparation and Stabilization of High Molecular Weight Poly (acrylonitrile-co-2-methylenesuccinamic acid) for Carbon Fiber Precursor

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3862
Author(s):  
Shuxian Zhang ◽  
Yanjin Dang ◽  
Xuepeng Ni ◽  
Chunshun Yuan ◽  
Huifang Chen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Carbon Fiber ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Reactivity Ratio ◽  
Exothermic Peak ◽  
Scanning Calorimetry ◽  
Monomer Feed ◽  
Poly Acrylonitrile ◽  
Carbon Fiber Precursor

Bifunctional comonomer 2-methylenesuccinamic acid (MLA) was designed and synthesized to prepare acrylonitrile copolymer P (AN-co-MLA) using mixed solvent polymerization as a carbon fiber precursor. The effect of monomer feed ratios on the structure and stabilization were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), X-ray diffraction (XRD), proton nuclear magnetic (1H NMR), and differential scanning calorimetry (DSC) for the P (AN-co-MLA) copolymers. The results indicated that both the conversion and molecular weight of polymerization reduce gradually when the MLA content is increased in the feed and that bifunctional comonomer MLA possesses a larger reactivity ratio than acrylonitrile (AN). P (AN-co-MLA) shows improved stabilization compared to the PAN homopolymer and poly (acrylonitrile-acrylic acid-methacrylic acid) [P (AN-AA-MA)], showing features such as lower initiation temperature, smaller cyclic activation energy, wider exothermic peak, and a larger stabilization degree, which are due to the ionic cyclization reaction initiated by MLA, confirming that the as-prepared P (AN-co-MLA) is the potential precursor for high-performance carbon fiber.

scholarly journals Biocompatibility studies of polyurethane electrospun membranes based on arginine as chain extender

2021 ◽  
Vol 32 (9) ◽  
Author(s):  
Georgina Alejandra Venegas-Cervera ◽  
Andrés Iván Oliva ◽  
Alejandro Avila-Ortega ◽  
José Manuel Cervantes-Uc ◽  
Leydi Maribel Carrillo-Cocom ◽  
...  
Keyword(s):  
Fourier Transforms ◽  
Cell Attachment ◽  
Human Fibroblasts ◽  
Gel Permeation Chromatography ◽  
Electrospinning Process ◽  
Chain Extender ◽  
Cellular Interaction ◽  
Scanning Calorimetry ◽  
Polyurethane Membranes ◽  
Electrospun Membranes

AbstractElectrospun polymers are an example of multi-functional biomaterials that improve the material-cellular interaction and aimed at enhancing wound healing. The main objective of this work is to fabricate electrospun polyurethane membranes using arginine as chain extender (PUUR) in order to test the fibroblasts affinity and adhesion on the material and the polymer toxicity. Polyurethane membranes were prepared in two steps: (i) the polyurethane synthesis, and ii) the electrospinning process. The membranes were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry techniques. The evaluation of PUUR as a scaffolding biomaterial for growing and developing of cells on the material was realized by LIVE/DEAD staining. The results show that the fluorescent surface area of human fibroblasts (hFB), was greater in control dense membranes made from Tecoflex than in electrospun and dense PUUR. From SEM analysis, the electrospun membranes show relatively uniform attachment of cells with a well-spread shape, while Tecoflex dense membranes show a non-proliferating round shape, which is attributed to the fiber’s structure in electrospun membranes. The cell morphology and the cell attachment assay results reveal the well spreading of hFB cells on the surface of electrospun PUUR membranes which indicates a good response related to cell adhesion.

scholarly journals Recycling Potential for Non-Valorized Plastic Fractions from Electrical and Electronic Waste

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 33
Author(s):  
Laura Strobl ◽  
Thomas Diefenhardt ◽  
Martin Schlummer ◽  
Tanja Leege ◽  
Swetlana Wagner
Keyword(s):  
Flame Retardants ◽  
Electronic Waste ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Separation Processes ◽  
Melt Flow Rate ◽  
Density Fractions ◽  
Material Recycling ◽  
Other Substances ◽  
Electrical And Electronic Waste

This paper describes a study for waste of electrical and electronic equipment (WEEE) to characterise the plastic composition of different mixed plastic fractions. Most of the samples studied are currently excluded from material recycling and arise as side streams in state-of-the-art plastics recycling plants. These samples contain brominated flame retardants (BFR) or other substances of concern listed as persistent organic pollutants or in the RoHS directive. Seventeen samples, including cathode ray tube (CRT) monitors, CRT televisions, flat screens such as liquid crystal displays, small domestic appliances, and information and communication technology, were investigated using density- and dissolution-based separation processes. The total bromine and chlorine contents of the samples were determined by X-ray fluorescence spectroscopy, indicating a substantial concentration of both elements in density fractions above 1.1 g/cm3, most significantly in specific solubility classes referring to ABS and PS. This was further supported by specific flame retardant analysis. It was shown that BFR levels of both polymers can be reduced to levels below 1000 ppm by dissolution and precipitation processes enabling material recycling in compliance with current legislation. As additional target polymers PC and PC-ABS were also recycled by dissolution but did not require an elimination of BFR. Finally, physicochemical investigations of recycled materials as gel permeation chromatography, melt flow rate, and differential scanning calorimetry suggest a high purity and indicate no degradation of the technical properties of the recycled polymers.

scholarly journals Rheological, Thermal, Superficial, and Morphological Properties of Thermoplastic Achira Starch Modified with Lactic Acid and Oleic Acid

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4433 ◽  
Author(s):  
Carolina Caicedo ◽  
Rocío Yaneli Aguirre Loredo ◽  
Abril Fonseca García ◽  
Omar Hernán Ossa ◽  
Aldo Vázquez Arce ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Oleic Acid ◽  
Complex Viscosity ◽  
Thermoplastic Starch ◽  
Residual Energy ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Acid Agent

The modification of achira starch a thermoplastic biopolymer is shown. Glycerol and sorbitol, common plasticizers, were used in the molten state with organic acids such as oleic acid and lactic acid obtaining thermodynamically more stable products. The proportion of starch:plasticizer was 70:30, and the acid agent was added in portions from 3%, 6%, and 9% by weight. These mixtures were obtained in a torque rheometer for 10 min at 130 °C. The lactic acid managed to efficiently promote the gelatinization process by increasing the available polar sites towards the surface of the material; as a result, there were lower values in the contact angle, these results were corroborated with the analysis performed by differential scanning calorimetry and X-ray diffraction. The results derived from oscillatory rheological analysis had a viscous behavior in the thermoplastic starch samples and with the presence of acids; this behavior favors the transitions from viscous to elastic. The mixture of sorbitol or glycerol with lactic acid promoted lower values of the loss module, the storage module, and the complex viscosity, which means lower residual energy in the transition of the viscous state to the elastic state; this allows the compounds to be scaled to conventional polymer transformation processes.

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