Polymer Characterisation Studies

TMA has been included in characterisation studies of phenol formaldehyde resin adhesives [14], colloidal copolymers containing hydroxyl, carboxyl and amide 

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These include studies on brittleness [37], adhesion and the use of DMTA in polymer characterisation studies [38,49, 83-90]. 

The main application areas for complementary size exclusion chromatography-mass spectroscopy (SEC-MS) are measurements of molecular weight (M ) or molecular mass distribution (MWD), polymer characterisation studies, end-group analysis and compositional analysis of copolymers. 

Polymer characterisation combinations of SEC and MS have been applied to polymer characterisation studies on a wide range of polymers and copolymers, some examples of which are discussed next. 

Polymers have inherently high hydrocarbon ratios, making liquefaction of waste plastics into liquid fuel feedstocks a potentially viable commercial process. The objective is to characterise the thermal degradation of polymers during hydrogenation. LDPE is studied due to its simple strueture. Isothermal and non-isothermal TGA were used to obtain degradation kinetics. Systems of homopolymer, polymer mixtures, and solvent-swollen polymer are studied. The significant variables for... 

Recent examples of the application of three-dimensional H/13C/Y correlation spectroscopy for the characterisation of polymers included studies of polystyrene samples obtained by diphenylphosphinyl radical initiated polymerisation of styrene (Y = 31P),38,39,86 and the characterisation of Sn-containing polybutadiene that was prepared by anionic polymerisation... 

TG-DTA Characterisation of carbon black [149], flammability evaluation [64], polymer degradation studies [65], ageing studies [70-72], product control [77, 81], combustion performance [83], safety evaluation [83], antioxidation activity [68], pyrolysis of rubbers [82], thermal stability [67, 69, 76, 77], interfacial junctions in viscoelastic composites [78], weathering [72], vulcanisation [73], oxidative behaviour [79], materials evaluation [80], failure analyses [81],... 

The techniques of polymer characterisation and of the application of SEC to biological studies is a broad and detailed subject and consequently this section can only provide a brief overview of the subject material. The interested reader is referred to the monographs by Hunt and Holding [90] and Dubin [91], and references therein. 

Active ultrasound uses a source of sound radiation, which is appHed to a process sample, with a detector placed such that modification to the signal can be detected and related to changes in the sample. Signal attenuation, velocity measurements and wavelength selective absorption provide the means of probing the sample. This approach promises to provide both chemical and physical information but as yet has not been used extensively. A number of on-line polymer-related studies have been reported in which polymer flow behaviour, viscosity, blend characterisation, and foaming-process monitoring have been examined [19]. 

Baranowski, R. and Whitmore, M. D. (1995). Journal of Chemical Physics 103,2343. Beredijk, N. (1963). Monomolecular film studies of polymers. Newer Methods of Polymer Characterisation. B. Ke. New York, Wiley-Interscience. 

Some examples of these applications include studies on p-hydroxybenzoic acid-6-hydroxy-2-naphthoic acid copolyester-based adhesives [269] and further miscellaneous studies on adhesion [270, 271]. West [272] has characterised medical polymers using XPS and ToF-SIMS. These two techniques have also been used to characterise carbon black surfaces [273] and carbon fibres [274]. Other workers have reviewed various aspects of the application of ToF-SIMS to polymer surface studies [237, 275-277] (See also Section 3.11.1). 

Due to the highly efficient nature of these polymer types as thickeners, viscosity-based characterisation studies are usually carried out on dilute solutions, typically at a concentration of < 1% polymer in water. Despite the non-Newtonian behaviour of these solutions (which is covered in more detail later in this chapter) useful information reflecting the character of the polymer present in solution can be obtained using cheap, simple and reliable equipment such as glass U-tube viscometers. 

The measurement of intrinsic viscosity using capillary viscometers can be a labour intensive and time-consuming exercise. However, polymer chemists undertaking characterisation studies in this way have been spared a significant amount practical work as a result of the development of so-called single point equations . These provide a method by which intrinsic viscosity can be determined when the flow time for the polymer solution is determined at only one concentration and compared to the flow time for that of the solvent alone. Solomon and Ciuta [23] proposed the following equation for use ... 

In comparison with the widespread use of single-stage MS in chemical analysis and in polymer analysis in particular [430], there has been little use of TG-MS/MS. Eor this analytical tool three specific areas can be considered (i) identification of unknown organic additives in compounded polymers [431] (ii) identification of volatile pyrolysates in polymer pyrolysis studies [403,404] and (Hi) characterisation of individual oligomers in low-MW polymers [432]. 

Field flow techniques have been reviewed in a number of articles [148-150]. Sedimentation field flow fractionation has found use in the separation of PVC [151, 152], polystyrene [151-153], poly(methyl methacrylate) [153, 154], poly (vinyl toluene) [155] and poly(glycidyl methacrylate) latexes [156] to produce particle-size distributions and particle densities. It has also been applied in polymer-aggregation studies [157], pigment [157] quality control and in the separation of silica particles [158] and its performance has been compared with that of ultracentrifugation [159]. Thermal field flow fractionation has been used successfully in the characterisation of ultra-high-molecular-weight polystyrenes [160, 161], poly(methyl methacrylate), polyisoprene, polysulphane, polycarbonate, nitrocellulose, polybutadiene and polyolefins [162]. In the difficult area of water-soluble polymers, poly(ethylene glycol), poly(ethylene oxide), poly(vinyl pyrrolidone) and poly(styrene sulphonate) have been analysed [163, 164]. In addition, compositional separations have been achieved for polystyrene-poly(methyl methacrylate) mixes [165] and comparisons between TFFF and SEC have been made [166]. 

In addition to polymer characterisation. X-ray photoelectron spectroscopy has been used in a variety of studies, as discussed in the following sections. 

These techniques are complimentary to each other, with each providing different information on structural details, polymer characterisation, structure and construction of existing and new polymers, measurement of polymer and copolymer composition, effect of catalysts and polymerisation, conditions on structure of polymers, hydrogen bonding in polymers, cis-trans measurement, optimum conditions for polymer synthesis, effect of polymer structure on thermal and crystallisation properties, effect of comonomer ratio on polymer structure and properties (for example, thermal and oxidative stability), tensile properties, and studies of competing reactions during polymerisation. 

FTIR-MALDI polymer and dendrimer characterisation and structure isotacticity, cyclo and oligolactides, polymerisation kinetics, molecular weight evaluations, diblock polymers-oligomer studies and cis-trans structures. 

Applications of scanning electron microscopy (SEM) to polymer characterisation and microstructure include studies on the zwitterions-type polymer, poly(3-diethyl methylmethacryloyl ethyl) ammonium persulfonate grafted on to a silica surface by treatment of poly(2-dimethyl amino) ethyl methacrylate [2], polyaniline coated glass fibre fillers with different polyaniline contents [3], and also studies on ultra high molecular weight blends [4] and high-density polyethylene (HDPE)-gamma ferric oxide composite films [5]. 

Polymer characterisation, stabilisation and degradation are very widely studied by Thermal Analysis (TA). Single techniques, such as thermogravimetric analysis (TG), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and dielectric thermal analysis (DETA) provide important information on the thermal behaviour of materials. However, to obtain a more complete profile of, say, polymer degradation gas analysis is required, particularly since all of the techniques listed give mainly physical information on the behaviour of materials. 

Characterisation studies have been carried out on the following polymers. Low density polyethylene [60], high density polyethylene [60, 61], t-butyl methacrylate-4-vinyl pyridine copolymer [62], styrene butadiene copolymer [63], PS [64-70], polyethylene oxide [64], polypropylene oxide [71, 72], glycidyl methacrylate [73],... 

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