Polymers

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15 pages, 2561 KiB

Open AccessArticle

The Effect of Feeding Sequence on the Structure and Properties of the Ethylene/1-Octene Copolymer in the Semi-Continuous Polymerization Reaction System

by Qiqi He, Ruijun Zhang, Yuexin Hu, Junhua Li, Hongbo Yu, Yong Zheng and Jianhua Qian

Polymers 2024, 16(4), 526; https://doi.org/10.3390/polym16040526 - 15 Feb 2024

Cited by 1 | Viewed by 685

Abstract

The performance of ethylene/1-octene copolymer primarily depends on the microstructure of the polymer chain. This study employed a new method to control the inter-distribution of hexyl chain branches directly on the backbone of the ethylene/1-octene copolymer. Three ethylene/1-octene copolymers with different inter-distributions of [...] Read more.

The performance of ethylene/1-octene copolymer primarily depends on the microstructure of the polymer chain. This study employed a new method to control the inter-distribution of hexyl chain branches directly on the backbone of the ethylene/1-octene copolymer. Three ethylene/1-octene copolymers with different inter-distributions of hexyl chain branches were synthesized using [Me₂Si(C₅Me₄) (N^tBu)] TiCl₂ (Ti–CGC) by different feeding sequences in the semi-continuous polymerization reaction system. The three copolymers were named according to the feeding sequence of the materials: ethylene/1-octene/Ti–CGC (EOC), 1-octene/Ti–CGC/ethylene (OCE), and ethylene/Ti–CGC/1-octene (ECO), respectively. The structure and properties of the copolymers were characterized using HT-GPC, ¹³C-NMR, DSC, WAXD, DMA, MI, and Uniaxial Tension Test. The results showed that the feeding sequence greatly affected the comonomer distribution of the molecular chains, molecular weight, molecular weight distribution, and chemical composition of the copolymers, consequently influencing their thermal performance and mechanical properties. Thus, it is probable that one could obtain an ethylene/1-octene copolymer with designed properties by controlling the feeding sequence during the ethylene/1-octene semi-continuous copolymerization process. Full article

(This article belongs to the Special Issue Covalent Organic Polymers: Synthesis and Applications)

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12 pages, 1774 KiB

Open AccessArticle

Vinylene-Linked Emissive Covalent Organic Frameworks for White-Light-Emitting Diodes

by Yan Li, Xiaohan Wu, Jinyi Zhang, Congcong Han, Mengmeng Cao, Xiangrong Li and Jieqiong Wan

Polymers 2023, 15(18), 3704; https://doi.org/10.3390/polym15183704 - 8 Sep 2023

Cited by 1 | Viewed by 1090

Abstract

Covalent organic frameworks (COFs) have gained considerable attention due to their highly conjugated π-skeletons, rendering them promising candidates for the design of light-emitting materials. In this study, we present two vinylene-linked COFs, namely, VL-COF-1 and VL-COF-2, which were synthesized through the Knoevenagel condensation [...] Read more.

Covalent organic frameworks (COFs) have gained considerable attention due to their highly conjugated π-skeletons, rendering them promising candidates for the design of light-emitting materials. In this study, we present two vinylene-linked COFs, namely, VL-COF-1 and VL-COF-2, which were synthesized through the Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with terephthalaldehyde or 4,4′-biphenyldicarboxaldehyde. Both VL-COF-1 and VL-COF-2 exhibited excellent chemical and thermal stability. The presence of vinylene linkages between the constituent building blocks in these COFs resulted in broad excitation and emission properties. Remarkably, the designed VL-COFs demonstrated bright emission, fast fluorescence decay, and high stability, making them highly attractive for optoelectronic applications. To assess the potential of these VL-COFs in practical devices, we fabricated white-light-emitting diodes (WLEDs) coated with VL-COF-1 and VL-COF-2. Notably, the WLEDs coated with VL-COF-1 achieved high-quality white light emission, closely approximating standard white light. The promising performance of VL-COF-coated WLEDs suggests the feasibility of utilizing COF materials for stable and efficient lighting applications. Full article

(This article belongs to the Special Issue Covalent Organic Polymers: Synthesis and Applications)

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Review

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29 pages, 8710 KiB

Open AccessReview

A Critical Review of Palladium Nanoparticles Decorated in Smart Microgels

by Muhammad Arif

Polymers 2023, 15(17), 3600; https://doi.org/10.3390/polym15173600 - 30 Aug 2023

Cited by 8 | Viewed by 1206

Abstract

Palladium nanoparticles (Pd) combined with smart polymer microgels have attracted significant interest in the past decade. These hybrid materials have unique properties that make them appealing for various applications in biology, environmental remediation, and catalysis. The responsive nature of the microgels in these [...] Read more.

Palladium nanoparticles (Pd) combined with smart polymer microgels have attracted significant interest in the past decade. These hybrid materials have unique properties that make them appealing for various applications in biology, environmental remediation, and catalysis. The responsive nature of the microgels in these hybrids holds great promise for a wide range of applications. The literature contains diverse morphologies and architectures of Pd nanoparticle-based hybrid microgels, and the architecture of these hybrids plays a vital role in determining their potential uses. Therefore, specific Pd nanoparticle-based hybrid microgels are designed for specific applications. This report provides an overview of recent advancements in the classification, synthesis, properties, characterization, and uses of Pd nanostructures loaded into microgels. Additionally, the report discusses the latest progress in biomedical, catalytic, environmental, and sensing applications of Pd-based hybrid microgels in a tutorial manner. Full article

(This article belongs to the Special Issue Covalent Organic Polymers: Synthesis and Applications)

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