Biodegradable synthetic polymers: Preparation, functionalization and biomedical application

Biodegradable polymers have been widely used and have greatly promoted the development of biomedical fields because of their biocompatibility and biodegradability. The development of biotechnology and medical technology has set higher requirements for biomedical materials. Novel biodegradable polymers with specific properties are in great demand. Biodegradable polymers can be classified as natural or synthetic polymers according to the source. Synthetic biodegradable polymers have found more versatile and diverse biomedical applications owing to their tailorable designs or modifications. This review presents a comprehensive introduction to various types of synthetic biodegradable polymers with reactive groups and bioactive groups, and further describes their structure, preparation procedures and properties. The focus is on advances in the past decade in functionalization and responsive strategies of biodegradable polymers and their biomedical applications. The possible future developments of the materials are also discussed.     

基于氟硼二吡咯的共轭聚合物研究进展

氟硼二吡咯（BODIPY）类功能染料因具有良好的光子及电子性质已经得到广泛的应用,对其共轭聚合物的研究则在近年受到广泛关注。与BODIPY单体相比,BODIPY的共轭聚合物具有更窄的带隙、吸收光谱的红移及更强的电子传导能力。BODIPY共轭聚合物在有机半导体材料及有机太阳能电池等方面具有广泛的应用前景。总结了BODIPY共轭聚合物的制备方法、结构与性质的关系以及应用等方面,提出了BODIPY共轭聚合物设计合成策略及未来的发展趋势。     

Synthesis and application of polyethylene-based functionalized hyperbranched polymers

Polyethylene is one of the largest volume commodity polymers, with excellent physical and chemical properties. Polyethylene-based functionalized hyperbranched polymers are newly developed materials with unique structures and properties. Their architecturally complex structure – topology, composition and functionality – may be designed for different applications, with reduction of complexity and cost in preparation. This review focuses on the synthesis strategies and applications of polyethylene-based functionalized hyperbranched polymers.     

Schiff Base Complexes in Macromolecules

Summary  Schiff base metal complexes are a class of compounds that have been studied extensively because of their attractive chemical and physical properties, and their wide-ranging applications in numerous scientific areas. Researchers have incorporated Schiff base complexes into polymers, generating new materials with useful mechanical, thermal, chemical, and electronic properties. This work comprehensively reviews the developments in macromolecules containing Schiff base metal complexes, emphasizing new synthetic strategies and characterization techniques that were used to prepare and study these polymers. This paper is dedicated to the pioneering research of Dr. Ian Manners.     

Transparent semi-crystalline polymeric materials and their nanocomposites: A review

Optical transparency is an important property for a material, especially in certain fields like packaging, glazing, and displays. Existing commercial transparent polymeric materials are mostly amorphous. Semicrystalline polymers have often-superior chemical resistance and mechanical properties particularly at elevated temperatures or after solid-state drawing but they appear opaque or white in most cases. This review describes the present state-of-the-art of methodologies of fabricating optically transparent materials from semicrystalline polymers. A distinction is made between isotropic, biaxially stretched, and uniaxially stretched semicrystalline polymers. Furthermore, some functionalities of transparent nanocomposites based on semicrystalline polymers are also discussed. This review aims to provide guidelines regarding the principles of manufacturing transparent high-performance semicrystalline polymers and their nanocomposites for potential applications in fields like packaging, building, and construction, aerospace, automotive, and opto-electronics.     

Recent application developments of water-soluble synthetic polymers

In the history of man-made macromolecules, water-soluble polymers have primarily maintained passive roles; examples include the uses of water-soluble polymers for viscosity control and as binders. The importance of water on earth has increased research into the development of active roles for water-soluble polymers. These expanding roles span from medical applications, such as drug delivery to environmental applications, such as the removal of heavy metals. The development of water-soluble polymers brings significant benefits to the structural engineering and production of nanomaterials and electronic materials. The current limits of the structure–property relationship have been challenged to meet these rapidly-developing application areas.     

Polylactic acid blends: The future of green,light and tough

Polylactic acid (PLA) is a biobased product and a compostable aliphatic polyester that has been studied for use in several applications over the last decade. Many properties of PLA, such as strength, stiffness, and gas permeability, have been found to be comparable to those of traditional petrochemical-based polymers. However, PLA-based materials exhibit a number of limitations for specific applications, such as slow biodegradation rate, high cost, and low toughness. The modification of PLA using the polymer blending technique to achieve suitable properties for different applications has been receiving significant attention over the past few years. Hence, the aim of this work is to summarize the current developments regarding the preparation and properties of PLA polymer blends. In this review, the recent advances in PLA preparation are broadly introduced. In addition, the miscibility and compatibilization strategies of PLA polymer blends are discussed. The preparations and characterizations of PLA blends with both biodegradable and non-biodegradable polymers are outlined. Finally, the biodegradation, mechanical properties, and potentiality of PLA blends are presented.     

Hierarchical modelling of polymeric materials

Within the last 20 years, computer simulations of materials have evolved from an academic curiosity to a predictive tool for addressing structure-property-processing-performance relations that are critical to the design of new products and processes. Chemical engineers, with their problem-oriented thinking and their systems approach, have played a significant role in this development.The computational prediction of physical properties is particularly challenging for polymeric materials, because of the extremely broad spectra of length and time scales governing structure and molecular motion in these materials. This challenge can only be met through the development of hierarchical analysis and simulation strategies encompassing many interconnected levels, each level addressing phenomena over a specific window of time and length scales.In this paper we will briefly discuss the fundamental underpinnings and example applications of new methods and algorithms for the hierarchical modelling of polymers. Questions to be addressed include: How can one equilibrate atomistic models of long-chain polymer melts at all length scales and thereby predict thermodynamic and conformational properties reliably? How can one quantify the structure of entanglement networks present in these melts through topological analysis and relate it to rheological properties? Are there ways to predict the microphase-separated morphology and stress-strain behaviour of multicomponent block copolymer-based materials, such as pressure sensitive adhesives? Is it possible to anticipate changes in the barrier properties of glassy amorphous polymers used in packaging applications as a consequence of modifications in the chemical constitution of chains?     

Nanofiber technology: current status and emerging developments

Nanofibers have emerged as exciting one-dimensional nanomaterials for a broad spectrum of research and commercial applications owing to their unique physicochemical properties and characteristics. As a class of nanomaterials with cross-sectional diameters ranging from tens to hundreds of nanometers, nanofibers possess extremely high specific surface area and surface area-to-volume ratio. They are capable of forming networks of highly porous mesh with remarkable interconnectivity between their pores, making them an attractive choice for a host of advanced applications. In fact, the significant impact of nanofiber technology can be traced from the wide range of fundamental materials that can be used for the synthesis of nanofibers. These include natural polymers, synthetic polymers, carbon-based materials, semiconducting materials, and composite materials. Correspondingly, the emerging proof-of-concept applications of nanofibers spanning several important areas have been rapidly reported. This Review explores the current status and up-and-coming development of nanofiber technology, with an emphasis on its syntheses and applications. First, we highlight the current and emerging strategies used in synthesizing nanofibers. We briefly introduce the various established nanofiber synthesis techniques, especially the electrospinning method. We then focus on the emerging nanofiber synthesis strategies, such as solution blow spinning, centrifugal jet spinning, and electrohydrodynamic direct writing. Next, we discuss the emerging applications of nanofiber technology in various fields, specifically in three important areas of energy generation and storage, water treatment and environmental remediation, and healthcare and biomedical engineering. Despite all these advancements, there are still challenges to be addressed and overcome for nanofiber technology to move towards maturation. Nevertheless, we envision that with further progress in the development of nanofiber synthesis strategies and identification of “killer” applications of nanofibers, nanofiber technology will mature and move beyond its current state towards commercial realization and applications.     

Modification of polythiophene by the incorporation of processable polymeric chains: Recent progress in synthesis and applications

Intrinsically conductive polymers (ICPs) have attracted significant attention in recent decades because of their wide range of potential applications in various fields such as chemistry, physics, electronics, optics, materials, and biomedical sciences. In particular, conjugated polythiophene (PTh) and its derivatives stand out as the most promising members of the conjugated polymer family because of their unique electrical behavior, excellent environmental and thermal stability, low-cost synthesis, and mechanical strength. However, similar to other π-conjugated polymers the main drawback of unsubstituted PTh is the lack of solubility due to its strong interchain interactions, resulting in limited processability. Various procedures have been invoked to overcome these restrictions, such as side chain functionalization, the synthesis of PTh copolymers with processable polymers, and combination of both of these strategies. Because of large number of publications on the chemical modification of polythiophene, this review is focused on progress in the synthesis of polythiophene copolymers with processable polymers. The properties of the polythiophene copolymers and their applications are also highlighted.     

Photoresponsive liquid crystalline block copolymers: From photonics to nanotechnology

Being one of the most fascinating multi-functional materials, photoresponsive liquid crystalline block copolymers (PLCBCs) have attracted much attention because of their light controllable properties of supramolecularly self-assembled structures. These originate from their unique features combining the advanced function of photoresponsive liquid crystalline polymers (PLCPs) with the inherent property of microphase separation of block copolymers (BCs). Benefiting from recent progresses in materials chemistry, diverse PLCBCs have been designed and synthesized by controlled polymerization using different synthetic routes and strategies. Generally, PLCBCs show different performance depending on their self-organization and molecular composition, with the PLCP blocks in the minority phase or in the majority phase. One of the most important properties of PLCBCs is supramolecular cooperative motion, resulted from the interactions between liquid crystalline elastic deformation and microphase separation, which enables them to self-assemble into regularly ordered nanostructures in bulk films with high reliability. These nanostructures contribute to improving the optical performance of polymer films by eliminating the scattering of visible light, in favor of their photonic applications. With the help of liquid crystal alignment techniques, both parallel and perpendicular patterning of nanostructures has been fabricated in macroscopic scale with excellent reproducibility and mass production, which provides nanotemplates and nanofabrication processes for preparing varieties of nanomaterials. Recent findings about PLCBCs including their synthesis, diagram of microphase separation, structure-property relationship, precise control of nanostructure as well as their applications in photonics to nanotechnology are reviewed.     

聚酰亚胺/无机纳米杂化材料的研究

聚酰亚胺是一种综合性能优异的材料,现已被广泛应用于航空航天及微电子领域.但是其明显的性能缺陷限制了其在高温和精密状态下的应用;而无机纳米粒子的引入,大大弥补了其性能缺陷（如较高的热膨胀系数和较低的吸水性）,非常适合对PI改性.本文阐述了PI纳米杂化材料的制备方法,介绍了纳米杂化材料的特点及应用.     

Design strategies of perovskite energy-storage dielectrics for next-generation capacitors

The next-generation capacitors have placed higher requirements on energy-storage dielectrics, such as high temperature, high frequency and high voltage. Perovskite dielectrics possess various kinds of polar structures, such as ferroelectric domains, polar nano-regions (PNRs), and anti-polar structure as well, which exhibit various responses to external stimulations (temperature, electric field, mechanical loadings). Its design inspires development strategies to improve their energy-storage properties for capacitors involving chemical composition, fabrication process, computer simulation, and even measurement strategies for validation. In this article, we reviewed the recent design strategies and the perovskite dielectrics (covering linear, ferroelectric, relaxor ferroelectric, anti-ferroelectric, even some composite materials, such as glass-ceramics and polymer). This review spans from the atomic to millimeter-scale strategies of property optimization to provide accurate and comprehensive information for researchers in this field. Some novel proposals for overcoming the barriers between materials and properties are presented to accelerate the applications of the next-generation capacitors. Therefore, this review should help to identify the best approach for transferring the new perovskite dielectrics into next-generation capacitor applications.     

Light and Shape-Memory Polymers: Characterization,Preparation, Stimulation,and Application

Shape-memory polymers (SMPs) are smart materials that change shape when exposed to stimuli and have various applications in different fields due to their unique properties. Light, as a kind of electromagnetic radiation, plays an important role in understanding the structure-property relations of SMPs, preparing original shapes, using them as non-contact stimuli sources, and tuning the optical properties of SMPs. This review provides a comprehensive review of the involvement of light in structure-preparation-stimuli-application of SMPs. The review is divided into four sections. First, applications of optical/spectroscopic approaches that provide information for understanding structure-property relations in SMPs, especially during programming and recovery. Second, describes how to build SMPs with light, including different photochemical reactions and 3D photocuring technologies. Third, discusses how light is used to trigger the shape change of SMPs through both photochemical and photothermal mechanisms. Last, focuses on how to take advantage of the shape-memory effect to tune the optical characteristics of polymers, including various structures of SMP color-changing materials and their synthetic strategies. Future research could focus on developing efficient photothermal fillers, new 3D printing techniques for SMPs, exploring their use in biomedical and wearable devices, and optimizing SMPs for industrial applications.     

Classification of properties of elastomers using the “optimum property concept.” I. Introduction

An attempt is made to distinguish properties of elastomers by types. “Basic properties of materials” or “network properties” in elastomers are properties which either increase or decrease from the liquid to the solid state of materials or over the range of the “elastomeric plateau” of elastomers. From these are distinguished properties that exhibit characteristic maxima and are therefore “maximum properties” or bivalued properties. Mechanical failure properties show the characteristics of “maximum properties.” The maxima in “maximum properties” generally do not coincide. This noncoincidence of the maxima with a change in a “basic property of a material” has major theoretical and practical implications, for example, it is the cause of the crossovers in the relative performance rating of materials under different test conditions. The implications of this noncoincidence of the failure property maxima on the relevance of correlations between these properties are discussed. A change in the testing conditions is reflected in a shift of the optimum value in a “basic property of a material” with respect to a specific “maximum property.” Data and certain conclusions in the literature are interpreted on the basis of this concept. Examples of the limitations of the validity of mathematical relationships are presented. Also, a definition of the term “state of cure” is proposed and a suggestion for the rating of severities of test equipment and applications of elastomeric materials recommended. The effect of increased degrees of crosslinking for a series of polymers and crosslinking agents is assessed. It is suggested that the “mechanisms” of failure properties will remain elusive if their rationalization is attempted on the basis of other failure properties, e.g., the mechanism of abrasion on that of tear strength or cut growth. The main purpose of this proposal is to provide support for a drastic reduction in laboratory testing by identifying those properties which can lead to different relative ratings in routine evaluations and actual applications. A more empirical approach to materials evaluations is recommended based on the calibration of laboratory instrumentation with respect to specific applications. A de-emphasis of routine evaluations of materials on the basis of their “maximum properties” seems to be justified.     

Side‐chain functionalized supramolecular polymers

Over the past two decades, the field of supramolecular polymer chemistry has developed from a curiosity to a mature area of polymer science. Among the most promising subjects in this large field are noncovalently functionalized side‐chain polymers that have been investigated extensively as a result of their modular character and ease of synthesis. Side‐chain functionalized polymers have the potential for a profound impact on complex materials. For example, for side‐chain functionalized polymers based on a single noncovalent interaction, materials for a variety of applications ranging from liquid crystalline and electro‐optical materials to drug delivery systems have been reported. Furthermore, materials based on this novel methodology may overcome several shortcomings of current covalent multifunctionalization strategies such as highly complex materials that are extremely difficult or impossible to fabricate with current methods. In this review, basic design requirements, advantages and potential applications are presented. Copyright © 2006 Society of Chemical Industry     

Synthesis and Properties of Polymers with an Organosilicon–Acetylene Backbone

Acetylene- and diacetylene-containing organosilicon polymers continue to be of great interest in academia, government, and industry due to their high thermo-oxidative stability combined with excellent solubility and processability characteristics. Progress in this field over the past 30 years is reported herein. We present and discuss the synthesis, characterization, and structure–property relationships related to these materials. Furthermore, properties for specific applications of these polymers are briefly summarized, such as absorption and emission spectroscopy, composite mechanical analysis, four-probe conductivity measurements, and electroluminescence.     

Evolution of supramolecular healable composites: a minireview

Efforts to further extend the range of applications of polymer based materials have resulted in the recent production of healable polymers that can regain their strength after damage. Within this field of healable materials, supramolecular polymers have been subject to extensive investigation. By virtue of their reversible non‐covalent interactions, cracks and fractures in such polymers can be readily and repeatedly healed in order to regain key physical properties. However, many supramolecular polymers are relatively weak and elastomeric in nature, which renders them unsuitable for high strength structural applications. To overcome these deficiencies, preliminary studies have shown that it is possible to reinforce supramolecular polymers with microscale and nanoscale fillers to afford composites that are not only stronger and stiffer compared with the polymers alone but also retain their healing abilities. In this minireview we discuss the evolution of these supramolecular composites and their advantages over more conventional, covalent polymeric materials. © 2014 Society of Chemical Industry     

新型金属-有机骨架配位聚合物（MOF）的研究龈

金属有机骨架配位聚合物结构多样,性质独特,具有广泛的应用前景,它已成为近几年来一个热门的研究领域,如今它因H2存储方面的潜力受到广泛关注。本文简要介绍该类配位聚合物作为一种新型的多孔材料,在结构和性能方面的研究进展。     

Nanofabrication with metallopolymers ‐ recent developments and future perspectives

Synthetic polymers containing metals and metal centers have experienced rapid growth in the last two decades. Metal‐containing polymers have an unprecedented role to play in modern high‐tech applications including nanomanufacturing, sensing, separation and catalysis. Advancement in synthetic strategies for macromolecules has enabled the synthesis of novel, exotic and use‐inspired metallopolymers. Using state‐of‐the‐art design strategies, it is now possible to perform targeted synthesis of macromolecules with varied complexity that contain a range of metal centers either in the backbone or in the side chains of the organic moiety. The presence of an inorganic element (metals and metal centers) in organic moieties has led to a number of new physicochemical properties while implementing novel functionality to the polymer matrix. This review covers nanotechnology influenced by distinctive features of metal‐containing macromolecular systems, particularly in developing flexible, functional materials. © 2013 Society of Chemical Industry