Injectable composites synthetic

The use of TAG as a curing agent continues to grow for polyolefins and olefin copolymer plastics and mbbers. Examples include polyethylene (109), chlorosulfonated polyethylene (110), polypropylene (111), ethylene—vinyl acetate (112), ethylene—propylene copolymer (113), acrylonitrile copolymers (114), and methylstyrene polymers (115). In ethylene—propylene copolymer mbber compositions. TAG has been used for injection molding of fenders (116). Unsaturated elastomers, such as EPDM, cross link with TAG by hydrogen abstraction and addition to double bonds in the presence of peroxyketal catalysts (117) (see Elastol rs, synthetic). 

As an anionic surfactant, a synthetic alkylate-base sulfonate containing about 60 % active material (Synacto 476) was used. To make it compatible with the injection water considered (composition in Table I) containing 1500 ppm Ca++ and Mg++ ions, a nonionic cosurfactant was combined with it, i.e. an unsaturated ethoxylated fatty alcohol with 8 ethylene oxide groups (Genapol). Their main characteristics and properties are listed in Table II. 

The synthesis of phtalocyanine dyes was followed by CE and the purity and composition of the end product was investigated by the same method. The chemical structure of the newly synthetized zinc phtalocyanine tetrasulphonic acid is shown in Fig. 3.163. An uncoated fused silica capillary (65cm X 75 /.an i.d.) was employed for the separation of dye components. Running buffers were 10 mM ammonium acetate (pH adjusted to 9.4 with ammonia) and 10 mM potassium dihydrogenphosphate (KH2P04) (pH = 9.0). Samples were injected hydrodynamically (50 mm for 10 s). Separation was realized in the constant current mode at 30 pA, which required about 28 kV separation voltage. Analytes... 

In this manner, all injections are of the same volume and of the same composition (within a factor of 2) the same amount of peptide are injected in runs 3 and 5 and absorbances of synthetic and native peptides should be about the same. Coelution run 6 will contain twice as much material as runs 3 and 5 and absorbance should be twice as intense as that seen in these runs. Such an experiment is illustrated in Figure 2. 

This polymer film composition can be extruded into a polymer film sheet laminated to or co-extruded with a thermoplastic synthetic resin sheet to make a thermoformable inner liner. The ther-moformable inner liner is thermoformed, trimmed, and nested in a spaced relationship within an outer wall element, after which a polymer foam is injected to the space between the inner liner and the outer wall element. 

Procedures of these 40 C (104 F) experiments are described in the Experimental Section. Tests were performed at a representative west Texas formation temperature using a typical west Texas stock tank oil and a synthetic brine having a composition typical of west Texas injection waters. Results are summarized in Table III. The ratio of foam volume after 30 minutes at 40 C to that after 1 minute was used as an indication of foam stability. The surfactants which produced the greatest initial (1.0 minute) foam volumes also exhibited the greatest foam stability over the thirty minute test period. Because test temperature and salinity were different than used in earlier experiments, results in the presence of west Texas stock tank oil cannot be compared to results described above. However, trends in foam stability were consistent with those described above. Average stability of the foams produced by the AEGS and AES surfactant classes was greater than that of the AE foams. 

Physicochemical testing is performed to characterize the physical and chemical properties of a plastic to insure that the composition of the synthetic medium will not compromise the quality of the drug being stored within it. To perform these tests, samples of plastic identical to the material being used in the primary package are subjected to an extraction procedure—to dissolve in an extraction solution leachable compounds that are at risk of entering the pharmaceutical preparation. This extraction solution is then subjected to analysis to evaluate the identity and quantity of leachants. For most plastics, the appropriate extraction medium is purified water, but elastomeric closures for use with injections should include extraction with three different extraction... 

In recent years starch, the polysaccharide of cereals, legumes and tubers, has acquired relevance as a biodegradable polymer and is becoming increasingly important as an industrial material (Fritz Aichholzer, 1995). Starch is a thermoplastic polymer and it can therefore be extruded or injection moulded (Balta Calleja et al, 1999). It can also be processed by application of pressure and heat. Starch has been used successfully as a matrix in composites of natural fibres (flax, jute, etc.). The use of starch in these composites could be of value in applications such as automobile interiors. An advantage of this biopolymer is that its preparation as well as its destruction do not act negatively upon the environment. A further advantage of starch is its low price as compared with conventional synthetic thermoplastics (PE, PP). 

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