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-- &#; A new set of polymers, which could act as flame retardant additives by blending with “commodity” polymers, was synthesized by chemically modifying poly (vinyl alcohol) (PVA) through reaction with a phosphorous-containing reagent.

Chemical modification of styrene based polymers with attaching antimicrobial -hydroxybenzoic acid group as a side chain Mehrdad Mahkam Department of Chemistry, Azarrbaijan University of Tarbiat Moallem, Tabriz, Iran.

-- &#; Silicon is shown to have a greater effect on flame retardance in the presence of halogen for each of the modified polymers. Elsevier Science Limited INTRODUCTION Chemical modification of preformed polymers is an established method of introducing function- ality to polymeric systems.'

New Chemical Modification of Polymers with Pendant Chloromethyl Groups Using ,-Diazabicyclo-[..]--undecene Download PDF. Published: February ; New Chemical Modification of Polymers ...

Chemical modification of polymers with flame‐retardant compounds Giuliana C. Tesoro Fibers and Polymers Laboratories, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts

-- &#; Sulfonation of Polystyrene Surfaces | Macromolecules. Chemical Modification of Polymers. . Sulfonation of Polystyrene Surfaces. An unusual example of intramolecular hydrogen bonding in a metal carbonyl cluster compound. Synthesis and crystal and molecular structure of di-.mu.-carbonylhexadecacarbonyldi-.mu.-hydroxo-.mu.-sulfidohexaruthenium.

-- &#; Phosphorylated polymers are versatile materials for a broad range of applications from flame-retardant coatings to bioactive scaffolds. Traditionally, they are synthesized in solution using corrosive concentrated phosphoric acid and energy-intensive drying techniques. In the past decade, mechanochemistry has proven to be a valuable tool for green chemists to conduct new …

-- &#; University of Massachusetts Amherst [email protected] Amherst Doctoral Dissertations - February -- Chemical modification of polymers and properties of

these polymers. Fluorinated polymers often suffer serious chain scission upon exposure to vacuum ultraviolet (VUV) radiation,but PET and polyethylene (PE) Surface Modification of Polymers by ...

-- &#; Chemical modification of polymers provided the opportunity to explore beyond conventional drug delivery. A thorough understanding of the polymer and its chemical modification has a huge potential to be the future trend for drug delivery and has many pharmaceutical applications.

-- &#; Surface-modified polymers are of substantial importance in many diverse aspects of modern technology, and whilst there are a number of existing physical and chemical methods for surface modification of polymers, the frequent requirement for significant infrastructure, harsh reaction conditions and limitation to specific polymer types led us to consider alternative chemical methods.

-- &#; (). Chemical Reactions on Polymers. II. Modification of Diene Polymers with Triazolinediones via the Ene Reaction. Journal of Macromolecular Science: Part A - Chemistry: Vol. , No. , pp. -.

-- &#; (). Chemical Modification of Polymers: Catalytic Hydrogenation and Related Reactions. Journal of Macromolecular Science, Part C: Vol. , No. , pp. -.

Flame retardance synthetic polymers Clays, natural or synthetic, are the most widely investigated and understood nanoadditives used to enhance the flame retardancy of polymers through nanocomposite technology, because of their unique properties, particularly the ease of surface treatment and application in polymer matrices.Clay can be cationic and anionic materials, in accordance with the ...

-- &#; Chemical Communications Light-induced modification of silver nanoparticles with functional polymers † Lukas Stolzer , ab Ishtiaq Ahmed , a Cesar Rodriguez-Emmenegger , ‡ bc Vanessa Trouillet , d Pascal Bockstaller , a Christopher Barner …

Publisher Summary Many polymers that are non-rubbers can be chemically modified to a relatively small extent to give products with very useful viscoelastic properties. These groups also allow vulcanization so that reversibly deforming, solvent-resistant products can be formulated. Starting with conventional rubber, it is possible, by means of chemical reactions, to convert the macromolecular ...

-- &#; The chemical modification of polymers, either by simple copolymerization techniques with monomers bearing flame-retardant groups or by post-polymerization modification, enables flame retardance to be achieved often at much lower levels of modification than necessary with additive-type, flame-retardant conventional, systems.

-- &#; The chemical modification of polymer chain by boron-containing groups leads to significant improvement in flame retardancy . It was found that the additives, such as boric acid, phenylboric acid and a number of other boronated compounds have no significant effect on PS flame retardancy.

Polymers of natural origin (gums, fibers, skins) have been used by man since prehistoric times. The technology of improving the useful qualities of such materials was developed empirically without benefit of the unifying conceptual framework of chemistry. The early chemical efforts which lead to the modification of rubber via isomerization with ...

Unlike many commercial coatings of hydrophilic polymers, PEG coating showed high stability even in high pH solution. Neither the removal of APS-PEG layers nor the chain cleavage of PEG took place. However, difunctional PEG-epoxide stored in . M salt pH solution showed significant alteration in electroosmosis due to the oxidation of epoxide ...

Flame retardation of polymers by chemical modification with phosphorus-containing compounds. Author: Banks, Mavis. ISNI: Awarding Body: University of Lancaster Current Institution: Lancaster University Date of Award: ...

The ease of modification naturally depends on the chemical nature of the starting material, but also on its physical form, particularly on whether it is linear (i.e. soluble), or cross-linked (i.e. insoluble). For insoluble polymers chemical reaction might occur only on the outer surface.

-- &#; The alternative method of flame retarding a polymer, namely by chemical modification, has several potential advantages such as: (a) low levels of modification may suffice; (b) the modifying groups are chemically attached and therefore less likely to be lost during the subsequent service; and (c) the modification can more readily be molecularly ...

Exchange of quaternary ammonium type anion exchange beads with NaBH leads to useful reducing agents possessing the advantage of easy work-up.

The resulting S-SEB-S/modified PPE nano-alloy exhibited both flexibility and flame retardancy, unlike other materials, where a trade-off exists between these two properties; that is, the flame ...

-- &#; The authors mainly intend to focus on the chemistries of phosphorous compounds, with the P atom being in different chemical environments, used either as reactive, or additive, fire retardants in styrene-based materials. The chemical pathways and possible mechanisms behind the fire retardance are discussed in this review.

Chemical modification and blending of polymers in an extruder reactor are discussed. Relationships between the parameters affecting the reaction kinetics, viz., mixing time, duration of a chemical reaction and the residence time of the system in the extruder reactor, and the structure of the materials produced are analysed.The mechanisms of (i) grafting of low-molecular-mass compounds onto ...

Flame retardants are chemical compounds when mixed or incorporated in to polymers provide varying degrees of flammability protection. Flammable polymeric materials are ubiquitous with a wide array ...

-- &#; Conant-Finkelstein reaction. g PVC was suspended in ml acetone, . g of NaI in ml acetone were added to this solution, and then the reaction (Fig. ) was carried out in a flask provided with stirrer, both at room temperature for h, and at oC for . h, …

-- &#; Mechanical Properties of Polymers Melting and glass transition temperature Polymer Additives ... • Colorants and Flame Retardants. Dr. M. Medraj Mech. Eng. Dept. - Concordia UniversityMECH lecture / ... chemical and structural changes take place at a

-- &#; capacity (section .) and flame resistance (section .) versus the truckload price of commercial polymers. Flammability and cost span over two orders of magnitude. The commodity polymers costing less than about $/pound comprise over % of the polymers in use, and these will continue to burn after brief exposure to a small flame.

-- &#; Chemical modification of polymers: . Dyeing of sulphonated polystyrene films by ion exchange with cationic dyes. Polymer , () , -.

-- &#; Novel modification of ethylene- vinyl alcohol copolymers were carried out. The modifications of series of the copolymers were carried out by reacting them with chloroacetyle chloride followed by amination with ethylene diamine which used for many applications, such as water sterilization, drugs, soil sterilization, biomedical-device sterilization, and prevention of the microbial contamination ...

-- &#; Modification of Polymer Properties provides, for the first time, in one title, the latest information on gradient IPNs and gradient copolymers. The book covers the broad range of polymer modification routes in a fresh, current view representing a timely …

Inorganic additives are commonly used because they are cheap, can be formulated with halogenated compounds, and can be used as fillers. Reactive-type methods are based on the chemical modification of polymers with flame retardant components, as opposed to additive-type methods [,,,,]. According to the composition, these retardants can ...

Polymer modification has been practiced since the very early technological development of human kind by transforming natural resources into value-added commodities. Ever since the middle of the last century in which petroleum-based polymers indisputably …

Request PDF | Chapter . The Chemical Modification of Polymers | Many polymers that are non-rubbers can be chemically modified to a relatively small extent to give products with very useful ...

-- &#; RECENT RESULTS ON CHEMICAL MODIFICATION OF POLYMERS PAUL REMPP Centre de Recherches sur les Macromolecules, (CNRS), , rue Boussingault— Strasbourg, Cedex, France Abstract—Some characteristic features of chemical transformations of polymers are examined on three examples: .