Biodegradable synthetic and semisynthetic polymers

As a part of our continuing interest in the preparation of multifunctional polymeric materials and evaluation of their potential in pharmaceutical, medical and environmental fields, a survey on new polymeric systems of synthetic and semisynthetic origin, susceptible to bioerosion and/or biodegradation attack is presented. In particular, attention has been focused on the design, preparation and characterization of the following classes of hydrophilic and/or water-soluble polymeric materials: hydroxyl-containing poly(ester)s, hydroxyl-containing poly(amide)s, hydrophilic polymers containing carboxylic groups, perhydroxylated oligo- and poly(saccharide)s, oxidized poly(saccharide)s, and hybrid polymeric materials based on blends of carboxyl-containing synthetic polymers and proteins. The rationale of the research activity undertaken over the years is illustrated by focusing on some specific achievements of practical significance.     

分子识别与温度响应复合智能材料

研究和开发具有双重和多重刺激响应型智能高分子材料已成为一个重要的发展方向。本文详细地综述了我们近年来在基于聚(N-异丙基丙烯酰胺)(PNIPAM)和β-环糊精(β-CD)的复合智能线型高分子、复合智能微球和复合智能膜方面的研究进展。不同形式的复合智能材料均采用相同的反应机理制备。综述了制备工艺条件、共聚单体比例、接枝率、客体分子种类和浓度等因素对于不同形式复合智能材料的温度响应性和分子识别特性的影响规律,并对复合智能膜在亲合分离、控制释放和手性拆分等方面的应用进行了介绍。评述了分子识别与温度响应复合智能材料的研究意义和发展方向,并对其应用前景进行了展望。     

RAFT‐based synthesis and the gelation property of telechelic polymers that can immobilize biomacromolecules

Telechelic polymers, macromolecules having two reactive end groups, can serve as building blocks for constructing polymers or polymeric materials that have complex architectures. Among the telechelic polymers, polymers bearing hydroxyl groups at two terminals have been used as components for preparation of functional materials. In the present study, RAFT polymerization of both N‐acryloylmorphorin and N‐succinimidyl acrylate by using a newly synthesized dithiobenzoate‐type chain transfer agent bearing hydroxyl groups at both terminals (HECPHD) was reported. After the acryloylation of the hydroxyl terminals of the obtained polymer, gelation was observed. Furthermore, the polymer could react with a protein via the conjugation of the succinimidyl esters‐containing polymers to the amino groups present on the protein surface. The results show that activated esters‐bearing polymers with hydroxyl groups at both terminals can be used as building blocks for constructing polymeric materials for an immobilization of biomacromolecules. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 1356–1365     

Development of fully functionalized photorefractive polymers

In this article, we review recent progress in the area of photorefractive polymers. Photorefractive (PR) polymers are multifunctional materials which combine photoconductivity and electro‐optic response to show a new phenomenon: light‐induced reversible modulation of the refractive index. Because of their multifunctional features, design, synthesis and preparation of these materials exhibiting high performance is an intellectual challenge. Moreover, numerous applications of photorefractive materials in optical devices have been established using inorganic materials. Utilizing the unique features of organic polymeric materials to prepare useful devices is an engineering challenge. In the past several years, research in this area has gained momentum because numerous new materials which possess better characteristic photorefractive parameters than their inorganic counterparts have been synthesized. Several interesting devices have been presented. Two different approaches have been developed to synthesize and prepare PR polymers, namely composite materials and fully functionalized polymers. Both approaches have had success in identifying new materials and in gaining understanding of the design principles of better materials. This paper discusses these aspects and gives a prospective view about this field.     

富勒烯功能高分子材料的制备与性能研究

对富勒烯功能高分子材料的制备、表征及其性能研究已成为光前国际上的前沿领域之一。从合成角度考虑,以不同的方法对Ｃ６０进行高分子修饰可得到结构、性质各异的富勒烯高分子衍生物,对于研究如何更好地控制Ｃ６０高分子衍生物的结构,探讨了有Ｃ６０参与的聚合反应的机理以及Ｃ６０在高分子衍生物中的作用无疑是很有帮助的。从应用角度考虑,Ｃ６０引入高分子中必将导致新型聚合物的产生。这些新型聚合物表现出许多独特而极具应用     

Carbohydrate polymers as controlled release devices for pesticides

Controlled release technology addresses problems associated with excessive use of toxic agricultural chemicals. This paper reviews the studies on the use of carbohydrate polymers as controlled release matrices for pesticides. Alginates, starch and its derivatives, chitosan, carboxymethylcellulose and ethylcellulose are some of the natural polymers discussed in this review. The advantages and disadvantages of these polymeric systems as well as the factors that affect pesticide release are presented. A discussion on the polymers’ encapsulation efficiency and release profile is also included, which will aid future researchers in identifying the suitable formulation for controlled release of pesticides. Combination of two polymers, incorporation of sorbents into polymer matrices, and modification of polymer systems are some of the strategies also discussed herein. Recent trends in this area of research include nanoformulation, nanoencapsulation, and the development of polymeric systems with dual properties such as controlled release with photo-protective property and the attract-and-kill strategy. Cytotoxicity studies are being conducted to address safety issues of pesticide handlers as well as to determine the toxicity of the formulation to non-target organisms such as the plant itself.     

Novel Trends in Ladder Polyheteroarylenes

Development of several fields of modern engineering has generated a need for the preparation of polymeric materials with working temperatures as high as 300°C. The solution of this problem is largely connected with preparation of new thermally stable polymers. As a consequence, beginning in the middle of the fifties, numerous investigations were carried out in order to obtain new thermally stable macromolecular compounds [1]. These investigations resulted in a considerable number of organo-element [1] and aromatic carbo-chain polymers [1] with a complex of valuable properties; but the chemistry of aromatic polymers containing various heterocycles in the main chains of macromolecules, so-called polyheteroarylenes, has received the most development [1].     

POLYSTYRYLSULFONYL CHLORIDE：A USEFUL，REACTIVE INTERMEDIATE FOR PREPARATION OF FUNCTIONALIZED POLYMERS

This paper describes the preparation of polystyrylsulfonyl chloride, a reactive intermediate,and its application in syntheses of functionalized polymers which can be used in organic chemistry as polymeric reagents, supports and in controlled release systems.     

Synthetic and biological polymers--merging the interface

The increasing control that synthetic chemists are able to exert over molecular architecture is allowing the design and preparation of macromolecular and polymeric systems of unprecedented sophistication. In form and function, synthetic polymers are able to mimic many biological polymers, in effect ‘blurring the boundaries’ between the worlds of artificial and natural materials. In this review, some key examples from the merging interface between synthetic and natural polymers are considered, and illustrations of both ‘bio-inspired’ synthetic macromolecular chemistry and new directions in polymer materials are given.     

Synthesis and characterization of polymethacrylate-based nitric oxide donors

A synthetic path for the preparation of methacrylic homo- and copolymers containing secondary amine groups that can be converted into nitric oxide (NO) releasing N-diazeniumdiolates is described. The polymers are obtained by a multistep procedure involving synthesis of methacrylate monomers containing boc-protected secondary amine sites, free radical benzoyl peroxide initiated polymerization, deprotection of the amine sites, and subsequent reaction of the polymers with NO in the presence of sodium methoxide. Monomers with both linear and cyclic pendant secondary amines are examined as polymer building blocks. In most cases, polymers are obtained for both types with compositions that agree well with initial monomer ratios and with number average molecular weights (M(n)) ranging from 1.69 to 2.58 x 10(6) Da. The final N-diazeniumdiolated methacrylic amine polymers are shown to release NO for extended periods of time with "apparent" t(1/2) values ranging from 30 to 60 min when suspended in phosphate buffer, pH 7.4. Total NO loading and release for these materials can reach 1.99 micromol per mg of polymer and is proportional to the amine content of the polymer. It is further shown that by using a dimethacrylate cross-linking agent in conjunction with the various methacrylate amines, suspension polymerization methods can be employed to create small (100-200 microm) polymeric methacrylate microbeads. Such microbeads that can be sequentially deprotected and converted to NO release particles via in-situ diazeniumdiolate formation as carried out for the non-crosslinked polymers.     

Weighing synthetic polymers of ultra‐high molar mass and polymeric nanomaterials: What can we learn from charge detection mass spectrometry?

Advances in soft ionization techniques for mass spectrometry (MS) of polymeric materials make it possible to determine the masses of intact molecular ions exceeding megadaltons. Interfacing MS with separation and fragmentation methods has additionally led to impressive advances in the ability to structurally characterize polymers. Even if the gap to the megadalton range has been bridged by MS for polymers standards, the MS‐based analysis for more complex polymeric materials is still challenging. Charge detection mass spectrometry (CDMS) is a single‐molecule method where the mass and the charge of each ion are directly determined from individual measurements. The entire molecular mass distribution of a polymer sample can be thus accurately measured. Described in this perspective paper is how molecular weight distribution as well as charge distribution can provide new insights into the structural and compositional studies of synthetic polymers and polymeric nanomaterials in the megadalton to gigadalton range of molecular weight. The recent multidimensional CDMS studies involving couplings with separation and dissociation techniques will be presented. And, finally, an outlook for the future avenues of the CDMS technique in the field of synthetic polymers of ultra‐high molar mass and polymeric nanomaterials will be provided.     

可释放一氧化氮的高分子材料

临床应用的许多生物医学装置在与血液或组织接触时,会导致装置表面血小板粘附、活化和血栓形成等,引发各种不良并发症,干扰这些装置的功能并产生毒副作用.一氧化氮是有效的血小板粘附和活化抑制分子.可产生和释放一氧化氮的高分子材料用于这些医学装置可以有效地抑制血小板的活化,防止血栓形成,提高其生物适应性.本文就近年来可产生和释放一氧化氮的高分子材料的制备和特性进行了综述.     

Preparation of polymer based sorbents for solid phase extraction of polyphenolic compounds

This article discusses the preparation of different polymeric sorbents for solid phase extraction. Various monomers like acrylamide, methacrylic acid and 4-vinylpyridine (VP), cross-linkers such as divinylbenzene (DVB) and ethyleneglycoldimethacrylate (EDMA), porogens like tetrahydrofuran (THF) and dimethylsulphoxide (DMSO) / acetonitrile (ACN) with different ratios were investigated in order to optimize recoveries. Resulting polymers were characterized through scanning electron microscope (SEM) and compared with Oasis HLB (Waters, MA, USA) and Strata-X (Phenomenex, Torrance, USA) on the basis of extraction performance, recovery efficiency and loading capacity. Sample applied was a mixture of flavonoid standards (rutin, myricetin, luteolin, quercetin, apigenin and kaempferol). HPLC hyphenated with PDA was used for the analysis of samples. Results showed that among the prepared SPE materials, 4-VP-co-EDMA produced best results. Comparison of the produced polymers with of Oasis HLB and Strata-X resulted in comparable efficiencies; especially the polymer 4-VP-co-EDMA gave almost similar results for all analytes to those of commercially available SPE materials. A general trend of decrease in retention efficiency with increase in polarity has been observed in both synthesized and already available SPE materials. The newly synthesized polymeric materials can be employed as SPE sorbents for efficient extraction of polyphenolic compounds especially for flavonoid aglycons.     

STUDIES ON STRUCTURE AND PHASE BEHAVIOR OF MULTICOMPONENT POLYMERS THROUGH RHEOLOGICAL TESTS

Rheological measurement has been a preferred approach to the characterization of the structure and phase behaviors for multi-component/multi-phase polymer systems, due to its sensitive response to the changes of structure for these heterogeneous polymers. In the present article, recent progresses in the studies on rheology for heterogeneous polymer systems including phase-separated polymeric blends and block copolymers are reviewed, mainly depending on the results by the authors＇ research group. By means of rheological measurements, not only some new fingerprints responsible for the evolution of morphology and structure concerning these polymer systems are obtained, also the corresponding results are significant for design and preparation of novel polymeric structural materials and functional materials.     

Developments in the use of soluble ionic polymers as pseudo-stationary phases for electrokinetic chromatography and stationary phases for electrochromatography

This article reviews the development, characterization and application of soluble ionic polymeric materials as pseudo-stationary phases for electrokinetic chromatography and as stationary phases for electrochromatography since 1997. Polymeric pseudo-stationary phases for electrokinetic chromatography, including cationic polymers, anionic siloxane and acrylamide polymers, polymerized surfactants (micelle polymers), and chiral polymers are reviewed. Also reviewed are suspended molecularly imprinted polymer micro-particles. Application of polymeric pseudo-stationary phases with electrospray ionization mass spectrometric detection is presented. Recent progress in the development and characterization of physically adsorbed stationary phases for electrochromatography using polymers of the same or similar chemistry is also reviewed.     

Fluorescence and Fourier-transform infrared spectroscopy for the analysis of iconic Italian design lamps made of polymeric materials

The preservation of design object collections requires an understanding of their constituent materials which are often polymeric blends. Challenges associated with aging of complex polymers from objects with an unknown physical history may compromise the interpretation of data from analytical techniques, and therefore complicate the assessment of the condition of polymers in indoor museum environments. This study focuses on the analysis of polymeric materials from three well-known Italian design lamps from the 1960s. To assess the degree of chemical modifications in the polymers, non-destructive molecular spectroscopic techniques, Fourier-transform infrared (FTIR) and fluorescence spectroscopy, have been applied directly on the object surfaces using an optical fiber probe and through examination of micro samples. FTIR spectra of the different polymers, polyvinylacetate (PVAc) for the lamps Taraxacum and Fantasma, and both acrylonitrile–butadiene–styrene polymer (ABS) and cellulose acetate (CA) for the lamp Nesso, allowed the detection of ongoing deterioration processes. Fluorescence spectroscopy proved particularly sensitive for the detection of molecular changes in the polymeric objects, as the spectra obtained from the examined lamps differ significantly from those of the unaged reference materials. Differences in fluorescence spectra are also detected between different points on the same object further indicating the presence of different chemical species on the surfaces. With the aid of complementary data from FTIR spectroscopy, an interpretation of the emission spectra of the studied polymeric objects is here proposed, further suggesting that fluorescence spectroscopy may be useful for following the degradation of historical polymeric objects.     

Antioxidant and spectroscopic studies of crosslinked polymers synthesized by grafting polymerization of ferulic acid

A novel, simple synthetic strategy for the preparation of crosslinked polymers with significant antioxidant properties is proposed. Ferulic acid (FA), a well‐known antioxidant compound, due to its reactivity toward free radical process, was inserted into a polymeric network with methacrylic acid (MAA) and ethylene glycole dimethacrylate acting as comonomer and crosslinker, respectively. All the reactants were simultaneously mixed in the polymerization feed and one‐pot radical reaction was carried out. Irregular microparticles were prepared by bulk polymerization and microspheres by precipitation polymerization. The materials were characterized by nuclear magnetic resonance–magic angle spinning (NMR‐MAS) studies, to verify effective FA insertion into polymeric networks, and by morphological, dimensional analyses, and water absorption measurement to study their superficial and swelling properties, respectively. Antioxidant properties of materials were evaluated by linoleic acid emulsion system–thiocyanate assay, determination of scavenging activity on DPPH radicals, determination of available phenolic groups in polymeric matrices, and determination of total antioxidant capacity. Copyright © 2009 John Wiley & Sons, Ltd.     

INVESTIGATION OF STRUCTURE AND PROPERTIES FOR POLYMER SYSTEMS BASED ON DYNAMIC RHEOLOGICAL APPROACHES

The dynamic theological measurements have been a preferred approach to the characterization of the structure and properties for multi-component or multi-phase polymer systems, due to its sensitive response to changes of structure for these heterogeneous polymers. In the present article, recent progresses in the studies on dynamic theology for heterogeneous polymer systems including polymeric composites filled with inorganic particles, thermo-oxidized polyolefins, phaseseparated polymeric blends and functional polymers with the scaling and percolation behavior are reviewed, mainly depending on the results by the authors‘ group. By means of theological measurements, not only some new fingerprints responsible for the evolution of morphology and structure concerning these polymer systems are obtained, the corresponding results are also significant for the design and preparation of novel polymer-based composites and functional materials.     

Nanostructures in polymer systems

General concepts concerning the formation, structure, and some properties of nanosized structural elements in polymers and polymeric materials are summarized from the standpoint of feasibility of formation of nanoparticles and nanoreactors in such systems and practical use of advantages offered by these structures. The familiar concepts are complemented with the results obtained recently. Examples are given to illustrate the implementation of elements of nanotechnology based on the principles of creation of nanostructures in amorphous and crystalline polymers, copolymers, and molecular composites. Practicable methods for the preparation of polymeric nanostructures by controlled crystallization, microphase and nanophase separation of components, and their dispersion, as well as the formation of interfaces, are discussed.     

Novel highly elastic magnetic materials for dampers and seals: Part I. Preparation and characterization of the elastic materials

The new generation of magnetic elastomers represents a new type of composites, consisting of small (mainly nano and micron‐sized) magnetic particles dispersed in a highly elastic polymeric matrix. The combination of polymers with magnetic materials displays novel and often enhanced properties. Highly elastic magnetic composites are quite new and understanding of the behavior of these materials depending on the composition, external conditions, and the synthesis processes is still missing. Thus, the aim of this work is the study of fundamental principles governing the preparation of these materials as well as their structure and elastic properties. Copyright © 2007 John Wiley & Sons, Ltd.