« Home « Kết quả tìm kiếm

Synthetic polymers

Tìm thấy 12+ kết quả cho từ khóa "Synthetic polymers"

Introduction to Modern Liquid Chromatography, Third Edition part 70

tailieu.vn

Size-exclusion chromatography (SEC) is reviewed in Section 13.8 and in [169];. its application for the determination of molecular weight or molecular-weight distribution (MWD) is similar for both synthetic polymers and biopolymers. For synthetic polymers, SEC is used to determine a molecular-weight distribution [169], whereas for biopolymers the goal is the estimation of molecular weight for individual compounds.

Chapter 069. Tissue Engineering (Part 2)

tailieu.vn

Scaffolds can be natural materials or synthetic polymers and are typically biodegradable. Natural materials such as collagen and alginates are biocompatible.. Synthetic polymers such as polyglycolic acid and polyethylene, on the other hand, can be tailored to provide more acceptable. Nonbiodegradable synthetic polymers such as polytetrafluoroethylene and polyethylene provide well-defined mechanical and structural properties.

Improvement of the mechanical and thermal properties of polyester nonwoven fabrics by PTFE coating

tailieu.vn

Industrial applications of nonwovens are limited by the intrinsic properties of their fiber-forming polymers. Different ways, including coating, have been developed to modify the surface properties of nonwovens.. Polyethylene terephthalate (PET) is one of the most important synthetic polymers due to its excellent properties and wide range of uses in the manufacturing of fibers and nonwoven textiles. 3,4 The chemical properties of PET make it easily flammable.

ASM Metals HandBook P16

tailieu.vn

In comparison to metals, intermetallics, and ceramics and glasses, polymers have very low CNs, which is part of the cause for their low densities. Elastomers are typified by natural rubber and by a series of synthetic polymers exhibiting similar mechanical behavior (e.g., polyisoprene).. Composites are relatively macroscopic arrangements of phases or materials designed to take advantage of the most desirable aspects of each.

HPLC for Pharmaceutical Scientists 2007 (Part 6)

tailieu.vn

All synthetic polymers consist of the mixture of the molecules of the same nature but different size (length, or number of repeat units), so we have to deal with average molecular weights when we work with polymers. The average molecular weight can be calculated in different ways, and each approach has its own value. In the Mark–Houwink equation (6-3) the intrin- sic viscosity is related to the molecular weight.

Introduction to Modern Liquid Chromatography, Third Edition part 74

tailieu.vn

Note that the mobile phases used in (a) and (d) are forbidden mobile phases for the coated version Chiralcel OD. 14.6.2 Synthetic-Polymer CSPs. A number of chiral synthetic polymers have been proposed as potential selectors, in an attempt to mimic the enantioselectivity of the semi-synthetic polysaccharides of Section 14.6.1. This may be the result of a much less ordered structure of the polymer chains, as well as the lack of pre-organized grooves and clefts for solute insertion.. the polymer.

Low molecular weight of hydroxyethyl cellulose to extract proteins in natural rubber latex

tailieu.vn

Low protein NRL was also prepared using synthetic polymers such as PVA with molecular weight (Mw) ~22,500 and 90,000 g/mol, PVP with Mw 40,000 and 360,000 g/mol at a concentration of 3 phr (part per hundred of rubber) [14]. The positively charged low molecular weight HEC combined with the negatively charged protein of NRL, producing soluble proteins that have been removed by centrifugation.

Catalytic activity of novel thermoplastic/cellulose-Au nanocomposites prepared by cryomilling

tailieu.vn

This has allowed the development of materials with improved properties, such as the introduction of cellulose fibers into synthetic polymers, which increased the strength and stiffness of the final product [6]. Thus, obtaining cellulose/thermoplastic-metal nanocomposites is usually an expensive and multistep process, consisting of the reduction of metal ions by reducing agents in a cellulose matrix, and then the incorporation of cellulose- metal nanoparticles into the thermoplastics [14,15].

Hydrophobic and hydrophilic drug loading capacity of micro diatom frustule from diatomite

tailieu.vn

Englert et al., “Pharmapolymers in the 21st Century: Synthetic Polymers in Drug Delivery Applications,” Prog. Sci., vol. Losic, “Acta Biomaterialia Graphene and graphene oxide as new nanocarriers for drug delivery applications,” Acta Biomater., vol. Med., vol. Brunner, “Biomimetic Control of Size in the Polyamine- Directed Formation of Silica Nanospheres,” Angew. Ed., vol. Nanobiotechnol., vol.

A novel molecular imprinting polymer for the selective adsorption of D-arabinitol from spiked urine

tailieu.vn

MIPs are synthetic polymers having specific cavities planned for a template molecule, which are synthe- sized by the copolymerization of functional and cross-linking monomers in the presence of a target analyte or template. In the most common preparation procedure, monomers make a complex with a template in the course of covalent or noncovalent interaction [20].

Preparation and property assessment of eco-friendly composite based on polyvinyl alcohol and lignin extracted from biomass

tailieu.vn

Among synthetic polymers, PVA has superior characteristics including nontoxicity, water-solubility, and hydrophilic with the presence of hydroxyl groups making it compatible with various biopolymer via the formation of hydrogen bonding at the interface [3]. Due to the diversity of its characteristics, PVA is used for many applications as water soluble films in agriculture and additives in textile, paper industries, and a variety of coatings.

Development of a molecularly imprinted polymer-based electrochemical sensor for tyrosinase

tailieu.vn

Two major concepts have been used: “evolution in the test tube” of nucleotides (aptamers) or total chemical synthesis of (molecularly imprinted) polymers. Molecular imprinting is a methodology used to create recognition sites in synthetic polymers by poly- merizing a functional monomer and a cross-linker in the presence of the target analyte, so-called “template”..

Synthesis, characterization, and biological activity of coordination polymers derived from pyromellitic dianhydride

tailieu.vn

Synthetic route for the coordination polymers.. Preparation of coordination polymers. All the coordination polymers were synthesized by using equimolar amounts of ligand and metal salt. To the above solution was added a solution of copper acetate (1.997 g, 0.01 mol) with constant stirring and the pH of the reaction mixture was adjusted to 4–5.

33 Synthetic Aperture Radar Algorithms

tailieu.vn

If we limit the synthetic aperture to a length so that the range from every array point in the aperture to a fixed surface location differs by less than λ/ 8, then the cross-range resolution of the unfocused SAR is limited to:. 33.2.3 Focused Synthetic Aperture Radar.

Synthesis of tetrakis bromine terminated phthalocyanine and its methyl methacrylate polymers via ATRP

tailieu.vn

The GPC traces of the synthesized ZnPc-PMMA polymers obtained at different reaction times are shown in Figure 5. GPC traces of the ZnPc-PMMA polymers.. The FTIR spectra of the ZnPc-PMMA polymers, ZnPc-Br and ZnPc-OH, are presented in Figure 6.

Effect of crosslinking patterns on the properties of conjugated microporous polymers

tailieu.vn

The polymers also exhibited altered spectral responses, which were explained via the change of the conjugation style and substituents along the backbone as a result of their different architectures. Friedel–Crafts alkylation to yield the traditional hypercrosslinked polymers or cross-coupling in the case of Yamamoto polymerization) or postsynthetic modifications (i.e.

Syntheses and photoluminescence properties of new Zn(II) and Cd(II) coordination polymers prepared from 5-sulfoisophthalate ligand

tailieu.vn

groups, was used to construct coordination polymers.

Recent synthetic methodologies for pyrimidine and its derivatives

tailieu.vn

Synthetic layout to achieve pyrimidine derivatives 163a and 163b.. Microwave-mediated reaction of obtained pyrimidine 165 with zinc cyanide in the presence of Pd(PPh 3 ) 4 followed by hydrolysis furnished pyrimidine derivatives 166.

In situ preparation of hetero-polymers/clay nanocomposites by CUAAC click chemistry

tailieu.vn

In situ preparation of hetero-polymers/clay nanocomposites by CUAAC click chemistry. Both clickable polymers, PEG-Alkyne and PCL-Alkyne, were simultaneously clicked on to azide-functional montmorillonite (MMT-N 3 ) nanoclay to get corresponding PEG-PCL/MMT nanocomposites. The combined XRD and TEM analysis confirmed that all PEG-PCL/MMT nanocomposites had partially exfoliated/. CuAAC click reactions have been applied for the preparation of poly(epsilon-caprolactone)-poly(ethylene glycol)/.

Introduction to Modern Liquid Chromatography, Third Edition part 62

tailieu.vn

POLYMERS, 648. 13.10.1 Background, 648. 13.10.2 Techniques for Polymer Analysis, 651. 13.10.3 Liquid-Chromatography Modes for Polymer Analysis Polymer Separations by Two-Dimensional Chromatography, 657. 13.1 BIOMACROMOLECULES. the HPLC versions of the first four techniques will be discussed here. 13.2 MOLECULAR STRUCTURE AND CONFORMATION 571. successful in the separation and characterization of peptides, and it serves as one of the major analytical tools for the development and characterization of