Search results for "Hyperbranched polymers"

Molecular parameters of hyperbranched polymers made by self-condensing vinyl polymerization of macroinimers

2000

The molecular weight averages and the degree of branching, DB, of a hyperbranched polymer obtained by self-condensing vinyl polymerization (SCVP) of a macroinimer A-(m)γ-B* is calculated by modifying the existing equations for SCVP. The polydispersity is lowered by a factor (γ + 1), where γ is the degree of polymerization of the macroinimer. DB decreases with γ, however, at full conversion the DB of the polymacroinimer is approximately 60% higher than expected from the “dilution” of an AB* inimer with linear m units. This is the result of the existence of a new kind of branched units. The structure of polymacroinimers is similar to the pattern of a highly branched copolymer obtained by self…

Amphiphilic Graft Copolymers and Hyperbranched Polymers Based on (3-Vinylphenyl)azomethyl-malonodinitrile

2001

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

2021

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2…

“Hard” Sphere Behavior of “Soft”, Globular-like, Hyperbranched Polyglycerols – Extensive Molecular Hydrodynamic and Light Scattering Studies

2020

Whether or not hyperbranched polymers behave like quasi “hard spheres” in solution is the subject of numerous fundamental discussions, also motivated by research on the perfectly branched dendrimer...

Linear–dendritic block copolymers: The state of the art and exciting perspectives

2011

Concurrent with the rapid development of both dendrimers and hyperbranched polymers, a novel class of block copolymer architectures has emerged from the combination of these dendritic architectures with linear chains, the “linear–dendritic block copolymers” (LDBCs). This review gives a comprehensive summary of the state of the art in this rapidly developing field from pioneering early work to promising recent approaches.The different strategies leading to these hybrid architectures with either perfect dendrimer/dendron building blocks or imperfect, yet more conveniently accessible hyperbranched segments, are reviewed and compared. The consequences of the unusual polymer topology for supramo…

Molecular Parameters of Hyperbranched Polymers Made by Self-Condensing Vinyl Polymerization. 2. Degree of Branching

1997

Using a modified definition, the average degree of branching, , the fraction of branchpoints, , as well as the fractions of various structural units are calculated as a function of conversion of double bonds for hyperbranched polymers formed by self-condensing vinyl polymerization (SCVP) of monomers (or “inimers”) with the general structure AB*, where A is a vinyl group and B* is an initiating group. The results are compared to those for the polycondensation of AB2-type monomers. At full conversion, is somewhat smaller for SCVP ( ∞ ≈ 0.465) than for AB2 systems ( ∞ = 0.5). There are two kinds of linear groups in SCVP whereas there is only one kind in AB2 systems. Since there are two differe…

Dielectric spectroscopy of novel thiol-ene/epoxy thermosets obtained from allyl-modified hyperbranched poly (ethyleneimine) and diglycidylether of bi…

2019

[EN] Dielectric Thermal Analysis (DETA) of a series of new thermoset obtained by click chemistry was performed. The new thermosets were obtained by a dual-curing process consisting in a first photochemical thiol-ene, followed by a thermal thiol-epoxy starting from an allyl-terminated hyperbranched poly(ethyleneimine) (HBPEI) and different proportions of diglycidylether of bisphenol A (DGEBA) and the corresponding stoichiometric proportions of pentaerythritol tetrakis (3-mercaptopropionate, PETMP). The dielectric behaviour was obtained experimentally supressing the conductive effects. Two sub-Tg intramolecular non-cooperative gamma and beta relaxations and an intermolecular cooperative alpha…

A convenient approach to amphiphilic hyperbranched polymers with thioether shell for the preparation and stabilization of coinage metal (Cu, Ag, Au) …

2014

Promising Dendritic Materials: An Introduction to Hyperbranched Polymers

2011

In nature and universe from living to nonliving things, branching occurs anywhere and anytime, such as the Crab Nebula, forked lightning, river basins, trees, nerves, veins, snow crystals, nervures, and proteoglycan ranging from light-years to kilometers, and to microscale and nanoscales (see Figure 1.1 for selected branching patterns). Hence, branching is a general and important phenomenon that could result in faster and more efficient transfer, dissipation, and distribution of energy and/or matter.

Hyperbranched polymer architectures: From Flory's AB(f-1) polycondensates to controlled structures

2020

Abstract Celebrating the 100th anniversary of Staudinger's “macromolecular concept”, polymer scientists critically evaluate the past developments and future challenges of polymer science, asking: Quo vadis, Macromolecular Science? The main focus in Polymer Science has been on linear polymers or crosslinked systems (elastomers and thermosets) until the late 1980ies. The advent of dendritic polymers, i.e. dendrimers and hyperbranched polymers (HBPs) attracted wide-spread attention in the polymer community. This article gives a brief overview of the developments in the area of hyperbranched polymers and demonstrates that they have since become a novel class of polymer materials.