Inorganic pigments and fillers

Encapsulation is the process of obtaining small solid nanoparticles, liquid nanodroplets or gas nanobubbles with a polymeric coating. We will give a historic account of some of the early work on encapsulating inorganic pigments and fillers with a polymer through (mini)emulsion polymerization. 

Besides inorganic pigment and filler partieles, there is also early work (from 1978) on encapsulation of organic pigments, e.g. eopper-phtaloeyanine and azo pigments [43]. For further reading on encapsulation of different materials see [44]. 

Identification of phases in polymers, 16 location of copolymers in blends, and identification of inorganic pigments and fillers... 

Carbon-black-filled materials defy spectral analysis, since featureless black-body emission is observed however, other highly filled polymers containing inorganic pigments and fillers can easily be analysed. FTIES has been applied to studies of in situ polymer degradation of carbon-black-free EPDM and Buna-N (nitrile) rubbers as 10 /u.m thick microtome cuttings [497]. ETIR emission has also been used for the characterisation of textile fibres [499] no special sample preparation is required as in case of transmission spectroscopy. It would be useful to collect a library of emission spectra of fibres. 

Examination of the THF-insoluble fraction. This fraction consists of inorganic pigments and fillers such as chalk, titanium dioxide, alumina trihydrate, clay, etc. fire retardants such as antimony trioxide lead-based stabilisers such as TBLS or DBLP polymeric impact modifiers that are totally insoluble in THF, such as MBS and various acrylic rubbers and polymeric impact modifiers that are partially soluble in THF, such as nitrile rubber and some grades of ABS which, while mainly insoluble in THF, will yield a fraction consisting of SAN which is soluble in THF and will be found with the precipitated polymer. 

These applications are a domain that is shared by UV and EB processes, because both can directly convert reactive liquids into solids almost instantly. There are specific areas where EB irradiation is more suitable than the UV curing process. In general, these include applications where thick layers of coatings or adhesives are applied. Other instances are coatings with high levels of inorganic pigments or fillers, which usually cannot be cured by UV radiation because of their opacity. As pointed... 

Most paints do not usually display as much diversity in chemistry, color, and layer structure as do automotive ones. Therefore, a wider variety of analytical instruments are often used to characterize them. Along with microscopy and IR spectroscopy, other methods frequently used are pyrolysis GC/MS and inorganic elemental analysis by X-ray spectroscopy in the SEM. X-ray diffraction is also of use in the identification of crystalline pigments and fillers. 

TG can also be used for the evaluation of the thermal stability of organic and inorganic pigments and pigmented polymeric samples [262]. Taking advantage of the chemistry of filler components. Gill-... 

Other applieations are examination of porous and pigmented or filled polymers (size, shape, distribution and orientation of pores or dispersed components), and the study of multicomponent and weathered materials. Examples are the determination of the distribution of rubber particles in ABS, the distribution of inorganic pigments or fillers in the surfaee (produetion of specks, irregular gloss) or in the layer proximate to the surface (haze) [135], The method is also suitable for quantitative eharacteri-sation of reinforeed composites. Mills et al. [151]... 

The microencapsulation of pigment and filler particles is an important area of research, both in academic research world and in industrial laboratories. Many activities in the past decade have been aimed at obtaining inorganic powders, coated with an organic polymer layer. Such systems are expected to exhibit properties other than the sum of the properties of the individual components. In general, several benefits from this encapsulation step can be expected when the particles are incorporated in a polymeric matrix (e.g. plastics or emulsion paints) ... 

As with most nonpolar hydrocarbon-intense polymers, bitumens exhibit good resistance to attack by inorganic salts and weak acids. They are dark, generally brown to black, and their color is difficult to mask with pigments. They are thermoplastic materials with a narrow service temperature range unless modified with fibrous fillers and/or synthetic resins. They are abundant materials that are relatively inexpensive, thus their use in many bulk applications. 

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