scholarly journals Effects of composition drift on the effectiveness of random copolymer reinforcement at polymer-polymer interfaces

2001 ◽  
Vol 39 (20) ◽  
pp. 2363-2377 ◽  
Author(s):  
J. J. Benkoski ◽  
G. H. Fredrickson ◽  
E. J. Kramer
Keyword(s):  
Random Copolymer ◽  
Polymer Interfaces ◽  
Composition Drift

scholarly journals Eco-Friendly Approach and Potential Biodegradable Polymer Matrix for WPC Composite Materials in Outdoor Application

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Alessia Quitadamo ◽  
Valerie Massardier ◽  
Marco Valente
Keyword(s):  
Polymer Blend ◽  
Glycidyl Methacrylate ◽  
Wood Flour ◽  
Random Copolymer ◽  
Tensile Tests ◽  
Poly Lactic Acid ◽  
Polymer Interfaces ◽  
Scanning Calorimetry ◽  
Future Studies ◽  
Outdoor Application

Blends based on high-density polyethylene (HDPE) and poly(lactic) acid (PLA) with different ratios of both polymers were produced: a blend with equal amounts of HDPE and PLA, hence 50 wt.% each, proved to be a useful compromise, allowing a high amount of bioderived charge without this being too detrimental for mechanical properties and considering its possibility to biodegradation behaviour in outdoor application. In this way, an optimal blend suitable for producing a composite with cellulosic fillers is proposed. In the selected polymer blend, wood flour (WF) was added as a natural filler in the proportion of 20, 30, and 40 wt.%, considering as 100 the weight of the polymer blend matrix. There are two compatibilizers to modify both HDPE-PLA blend and wood-flour/polymer interfaces, i.e., polyethylene-grafted maleic anhydride and a random copolymer of ethylene and glycidyl methacrylate. The most suitable percentage of compatibilizer for HDPE-PLA blends appears to be 3 wt.%, which was selected also for use with wood flour. In order to evaluate properties of blends and composites tensile tests, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analyses, and infrared spectroscopy have been performed. Wood flour seems to affect heavy blend behaviour in process production of material suggesting that future studies are needed to reduce defectiveness.

CHEMISTRY AND MICROSTRUCTURE AT METAL-POLYMER INTERFACES

1988 ◽  
Vol 49 (C5) ◽  
pp. C5-49-C5-59 ◽  
Author(s):  
P. S. HO ◽  
R. HAIGHT ◽  
R. C. WHITE ◽  
B. D. SILVERMAN
Keyword(s):  
Polymer Interfaces ◽  
Metal Polymer

scholarly journals Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Microphase Separation ◽  
Triblock Copolymers ◽  
Random Copolymer ◽  
Thermomechanical Properties ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Central Block ◽  
Quadruple Hydrogen Bonding

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.

scholarly journals Synthesis, Characterization and Bactericidal Activity of a 4-Ammoniumbuthylstyrene-Based Random Copolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Random Copolymer ◽  
Water Soluble ◽  
Cationic Polymers ◽  
Severe Infections

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.

scholarly journals Cationic Copolymerization of Isobutylene with 4-Vinylbenzenecyclobutylene: Characteristics and Mechanisms

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 201 ◽  
Author(s):  
Zhifei Chen ◽  
Shuxin Li ◽  
Yuwei Shang ◽  
Shan Huang ◽  
Kangda Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cationic Polymerization ◽  
Transfer Reaction ◽  
Chain Transfer ◽  
Solid Phase ◽  
Random Copolymer ◽  
Glass Transition Temperatures ◽  
Cationic Copolymerization ◽  
Chain Transfer Reaction

A random copolymer of isobutylene (IB) and 4-vinylbenzenecyclobutylene (4-VBCB) was synthesized by cationic polymerization at −80 °C using 2-chloro-2,4,4-trimethylpentane (TMPCl) as initiator. The laws of copolymerization were investigated by changing the feed quantities of 4-VBCB. The molecular weight of the copolymer decreased, and its molecular weight distribution (MWD) increased with increasing 4-VBCB content. We proposed a possible copolymerization mechanism behind the increase in the chain transfer reaction to 4-VBCB with increasing of feed quantities of 4-VBCB. The thermal properties of the copolymers were studied by solid-phase heating and crosslinking. After crosslinking, the decomposition and glass transition temperatures (Tg) of the copolymer increased, the network structure that formed did not break when reheated, and the mechanical properties remarkably improved.

scholarly journals Changes in Thermodynamic Interactions at Highly Immiscible Polymer/Polymer Interfaces due to Deuterium Labeling

2006 ◽  
Vol 110 (22) ◽  
pp. 10602-10605 ◽  
Author(s):  
Shane E. Harton ◽  
Frederick A. Stevie ◽  
Zhengmao Zhu ◽  
Harald Ade
Keyword(s):  
Polymer Interfaces ◽  
Deuterium Labeling ◽  
Immiscible Polymer

Effect of Density Fluctuating Supercritical Carbon Dioxide on Polymer Interfaces

Langmuir ◽  
2005 ◽  
Vol 21 (14) ◽  
pp. 6157-6160 ◽  
Author(s):  
Tadanori Koga ◽  
J. L. Jerome ◽  
Y.-S. Seo ◽  
M. H. Rafailovich ◽  
J. C. Sokolov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Polymer Interfaces ◽  
Supercritical Carbon
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