Targeted Copolymerization in Amorphous Regions for Constructing Crystallizable Functionalized Copolymers

Abstract

Heavily damaged or disappeared crystallizability caused by nonselective chemical binding of functional units is a universal and challenging issue for random functionalized copolymers. Herein, we propose a temperature-controlled targeted copolymerization that can selectively activate the amorphous region segments of polymers and directionally copolymerize the functional units into this region while retaining the regular segments and crystallizability of the original crystalline region. A flame-retardant functional monomer and typical semicrystalline polyester are chosen to verify our state-of-the-art targeted copolymerization approach. Compared with the corresponding random copolymers, the resulting microblock copolymers exhibit a much higher crystallinity and faster crystallization rate while keeping other functionalities. Even at a high functional unit content (16.7 mol %), targeted copolymerization can endow copolymers with good crystallinity, while the corresponding random copolymer is totally noncrystallizable. Hence, targeted copolymerization chemistry provides a pioneering opportunity to achieve functionalization and maximum retention of crystallization ability at the same time, allowing purposeful tailoring of macroscopic performance by precisely regulating the sequential distribution of microstructure units.

“Hetero-Furan Unit” Drives a Spontaneous Leaf-Vein Bioinspired Multiscale Design for Ultra-Robust, Lightweight, and Recyclable Polymers

“…Typically, polymer spherulites are independently dispersed in continuous amorphous regions and act as physical cross-linking points. The size, orientation distribution, and crystallinity of spherulites play a very important role in macroscopic properties, such as density, transparency, mechanical strength, and toughness of polymer materials. − Therefore, our idea is to construct continuous and interpenetrating crystal regions similar to a leaf-vein multiscale network in the polymer matrix (Figure c), so as to achieve the purpose of mechanical self-reinforcement and self-toughening. Since the crystal and amorphous regions belong to the same polymer, it represents likely the best recycling option without separating the filler and matrix.…”

Macromolecular Postpolymerization of Siloxane Exchange to Assemble Multiple Siloxane Linkages

“…The possibilities of polymerization, and the variety of products that can be gained, are greatly increased when polymerization is carried out in a mixture of two or more monomers, for the copolymer chain can now contain arrangements of various monomer units. − Moreover, copolymerization brings flexibility to tailor polymer properties (such as Tg , surface energy, rheological properties, and so on) to meet the needs of a wide range of applications. − However, copolymerization is a more challenging research topic than homopolymerization, because it requires a comprehensive consideration of the relative polymerization activity of monomers, monomer feeding ratios, and dosing methods, and the distribution of monomers (random, block, or alternating) in the polymer chain. − Therefore, numerous efforts have been devoted to the development of catalysts and polymerization methods to surmount the varied polymerization activity of the monomers and to achieve the controllability of the copolymerization, thus modulating the properties of the synthesized polymers. , Such challenges are also encountered with polysiloxanes, − a polymer formed out of silicon and oxygen atoms alternately arranged in the backbone and organic groups attached to the silicon atoms, which serve as a critically important material bridge between inorganic and organic polymers.…”

Synthesis and application of poly (cyclotriphosphazene‐resveratrol) microspheres for enhancing flame retardancy of poly (ethylene terephthalate)

“…Consequently, PET has been extensively used for the fabrication of engineering plastics, textile fibers, foams, bottles, and other specific materials 1,2 . However, inflammability and serious melt‐dripping constrict the applications of PET in different fields 3,4 . In particular, the heavy melt‐dripping after ignition and toxic smoke production of PET in a short time may also cause serious threats to human health and ecological environment 5 .…”

“…1,2 However, inflammability and serious meltdripping constrict the applications of PET in different fields. 3,4 In particular, the heavy melt-dripping after ignition and toxic smoke production of PET in a short time may also cause serious threats to human health and ecological environment. 5 Therefore, circumventing the limitations associated with the flammability and melt-dripping of PET materials is of considerable significance problem.…”