Search results for "plastics"
showing 10 items of 2724 documents
Macromol. Chem. Phys. 2/2017
2017
Cover Picture: Macromol. Chem. Phys. 17/2004
2004
Macromol. Chem. Phys. 10/2009
2009
Hans Wolfgang Spiess 60
2002
Macromol. Chem. Phys. 14/2008
2008
Sterospecific polymerization with alkali metal organic compounds
1962
Temperature Variation Enables the Design of Biobased Block Copolymers via One‐Step Anionic Copolymerization
2021
A one-pot approach for the preparation of diblock copolymers consisting of polystyrene and polymyrcene blocks is described via a temperature-induced block copolymer (BCP) formation strategy. A monomer mixture of styrene and myrcene is employed. The unreactive nature of myrcene in a polar solvent (tetrahydrofuran) at -78 °C enables the sole formation of active polystyrene macroinitiators, while an increase of the temperature (-38 °C to room temperature) leads to poly(styrene-block-myrcene) formation due to polymerization of myrcene. Well-defined BCPs featuring molar masses in the range of 44-117.2 kg mol-1 with dispersities, Ð, of 1.09-1.21, and polymyrcene volume fractions of 30-64% are acc…
Thioether-Bearing Hyperbranched Polyether Polyols with Methionine-Like Side-Chains: A Versatile Platform for Orthogonal Functionalization
2016
The synthesis of thioether-bearing hyperbranched polyether polyols based on an AB/AB2 type copolymerization (cyclic latent monomers) is introduced. The polymers are prepared by anionic ring-opening multibranching copolymerization of glycidol and 2-(methylthio)ethyl glycidyl ether (MTEGE), which is conveniently accessible in a single etherification step. Slow monomer addition provides control over molecular weights. Moderate dispersities (Đ = 1.48–1.85) are obtained, given the hyperbranched structure. In situ 1H NMR copolymerization kinetics reveal reactivity ratios of rG = 3.7 and rMTEGE = 0.27. Using slow monomer addition, copolymer composition can be systematically varied, allowing for th…
Temperature Sensing in Cells Using Polymeric Upconversion Nanocapsules
2020
Monitoring local temperature inside cells is crucial when interpreting biological activities as enhanced cellular metabolism leads to higher heat production and is commonly correlated with the presence of diseases such as cancer. In this study, we report on polymeric upconversion nanocapsules for potential use as local nanothermometers in cells by exploiting the temperature dependence of the triplet-triplet annihilation upconversion phenomenon. Nanocapsules synthesized by the miniemulsion solvent evaporation technique are composed of a polymer shell and a liquid core of rice bran oil, hosting triplet-triplet annihilation upconversion active dyes as sensitizer and emitter molecules. The sens…
Aging of Nanosized ZnO Modified Polyoxymethylene Blends with Ethylene–octene Copolymer
2015
The influence of ethylene–octene copolymer and zinc oxide (ZnO) on structure and tensile stress–strain behavior of polyoxymethylene were investigated before and after ultraviolet weathering. Addition of ZnO considerably improved stress–strain characteristics of the ultraviolet-irradiation impaired composites. Crystallinities of ultraviolet-irradiated composites were affected by numerous competitive processes, including suppression of crystallization in the presence of multiple components in the system, nucleation induced by nanofiller, secondary crystallization and amorphization because of the chain scissions of the macromolecules. Addition of ZnO considerably improved stability of the comp…