Search results for "Multiblock copolymer"

Sacrificial Synthesis of Hydroxy-Telechelic Metathesis Polymers via Multiblock-Copolymers

2009

The synthesis of well-defined telechelic ring-opening metathesis polymers has been achieved by Sacrificial Synthesis. With the formation of cleavable triblock-copolymers, precise control over the molecular weight and the degree of functionalization was achieved. Introducing cleavable monomers that can be addressed separately, sequential deprotection was accomplished which opened the path to more sophisticated polymeric materials bearing different substituents at their respective chain ends. Sacrificial penta- and heptablock-copolymers are also presented which allow the synthesis of well-defined telechelic polymers in good yields and significantly improved initiator efficiency.

Tapered Multiblock Copolymers Based on Isoprene and 4-Methylstyrene: Influence of the Tapered Interface on the Self-Assembly and Thermomechanical Pro…

2019

The synthesis of tapered multiblock copolymers by statistical living anionic copolymerization of a mixture of isoprene (I) and 4-methylstyrene (4MS) in cyclohexane is based on vastly different reac...

Anionic Copolymerization Enables the Scalable Synthesis of Alternating (AB)n Multiblock Copolymers with High Molecular Weight in n/2 Steps

2018

Based on the highly disparate reactivities of isoprene (I, rI = 25.4) and 4-methylstyrene (4MS, r4MS = 0.007) in the anionic copolymerization in nonpolar media, a general strategy for the rapid and scalable synthesis of tapered multiblock copolymers with an extremely steep gradient has been developed. A repetitive addition strategy of a mixture of isoprene and 4MS leads to a tapered diblock in each case, giving access to linear alternating multiblock copolymers of the (AB)n type with up to 10 blocks. All multiblock copolymers showed narrow molecular weight distributions (dispersity Đ = 1.04–1.12). High molecular weights in the range of 80 to 400 kg mol–1 were achieved. Due to the incompatib…

Phase Diagram of Random Copolymer Melts:  A Computer Simulation Study

2004

We investigate the phase behavior of random copolymer melts via large-scale Monte Carlo simulations. The AB multiblock copolymers have, on average, symmetric composition and are characterized by a ...

Local and Subchain Relaxation of Polyisoprene in Multiblock Copolymers with a Tapered Interface

2020

We report on the local and (sub-) chain dynamics in a new class of tapered multiblock copolymers synthesized by the repeated statistical living anionic copolymerization of a mixture of isoprene and...

Building Bridges by Blending: Morphology and Mechanical Properties of Binary Tapered Diblock/Multiblock Copolymer Blends

2021

Dynamic Self-Consistent Field Approach for Studying Kinetic Processes in Multiblock Copolymer Melts

2020

The self-consistent field theory is a popular and highly successful theoretical framework for studying equilibrium (co)polymer systems at the mesoscopic level. Dynamic density functionals allow one to use this framework for studying dynamical processes in the diffusive, non-inertial regime. The central quantity in these approaches is the mobility function, which describes the effect of chain connectivity on the nonlocal response of monomers to thermodynamic driving fields. In a recent study [Mantha et al, Macromolecules 53, 3409 (2020)], we have developed a method to systematically construct mobility functions from reference fine-grained simulations. Here we focus on melts of linear chains …

Tapered Multiblock Copolymers Based on Farnesene and Styrene: Impact of Biobased Polydiene Architectures on Material Properties

2020

The reactivity of the biobased monomer β-farnesene in the statistical anionic copolymerization with styrene and the effect of the bottlebrush-like polyfarnesene structure on the phase separation be...

Isoprene/Styrene Tapered Multiblock Copolymers with up to Ten Blocks: Synthesis, Phase Behavior, Order, and Mechanical Properties

2018

The living anionic copolymerization of isoprene and styrene in cyclohexane affords tapered block copolymers due to the highly disparate reactivity ratios of rI = 12.8 and rS = 0.051. Repeated addit...

Vascular Endothelial Growth Factor-Releasing Microspheres Based on Poly(ε-Caprolactone-PEG-ε-Caprolactone)-b-Poly(L-Lactide) Multiblock Copolymers In…

2020

Pancreatic islet transplantation is a promising advanced therapy that has been used to treat patients suffering from diabetes type 1. Traditionally, pancreatic islets are infused via the portal vein, which is subsequently intended to engraft in the liver. Severe immunosuppressive treatments are necessary, however, to prevent rejection of the transplanted islets. Novel approaches therefore have focused on encapsulation of the islets in biomaterial implants which can protect the islets and offer an organ-like environment. Vascularization of the device’s surface is a prerequisite for the survival and proper func- tioning of transplanted pancreatic islets. We are pursuing a prevascularization s…