Alternative plastics

When dry, casein is a good electrical insulator but is seriously affected by humid conditions. For this reason it can no longer compete with the many alternative plastics materials now available for electrical applications. 

Alternately, plastic finger-tight fittings (e.g., UpChurch) are convenient and easy to use, but they do have a tendency to slip at a higher pressure. 

Chemical Substitution Phthalates are used to provide flexibility to the polymer backing. The use of alternative plasticizers represents the most direct method of substitution. In some cases this choice may have little impact on production techniques, and so be the most economically favourable option in immediate terms. 

Shutdown of Oxochem s 2-ethylhexanol unit in 1978 eliminated 300 million pounds of capacity overnight. As a result, DOP users began a crash reformulation effort on alternative plasticizers. Linear alcohol and Cg and Ciq branched chain alcohol based phthalates as well as butyl benzyl phthalate, for example, were found to be wholly or partially substitutable plasticizers in many DOP applications. New 2-ethylhexanol capacity available starting in 1981 is expected... 

The system selects a plasticizer and checks that there are no stability/compatibility problems. If positive, the user is asked to select an alternative plasticizer. 

Shekarchi et al. (1982) used stainless steel microsticks coated with carrier material. Alternatively, plastic microsticks are available from Dynatech Laboratories. Irrespective of their nature (steel, teflon, polystyrene), they may be coated with polycarbonate or nitrocellulose. The latter is applied as a thin film of colloidon diluted with 4 volumes of ether (laboratory grade). The microsticks are dipped in this solution, dried and arranged in a transfer plate designed for use in a microtitre plate. They can be cleaned with 6 N HCl after use. 

K. Grage, V. Peters, R. Palanisamy, B.H.A. Rehm, Polyhydroxyal-kanoates from bacterial storage compound via alternative plastic to bio-bead, in B.H.A. Rehm (Ed.), Microbial Production of Biopolymers and Polymer Precursors Applications and Perspectives, Caister Academic Press, Norfolk, UK, 2009, pp. 255-287. 

The toymaking branch has responded both by turning to alternative plasticizer systems, for example based on citric acid esters, or to different types of plastics altogether, mainly so-called thermoplastic elastomers (TPEs). 

Although organic contaminants from the abraded tire material are apparently not enriched in the soil, some manufacturers are switching to alternative plasticizer oils with low PAH contamination levels [17, 18]. 

Under these popular pressures, manufacturers began to look for alternative plasticizers. CSTEE does not support use of other alternative plasticizers because there is not enough data on the health risks of citrates and adipates considered as potential replacements. Moreover, it was found that a reliable method of analysis of the amount of plasticizer migration does not exist and cannot be used with a legislative purpose in mind. " ... 

Some of the supported Ru catalysts were evaluated for phthalate hydrogenation activity [23]. The reaction is shown in Figure 16.9. Ru selectively hydrogenates the aromatic ring of the phthalate ester and this reaction offers a route to an alternative plasticizer precursor for polyvinyl chloride polymers. 

A flooring manufacturer (Tarkett North America) announced a switch from conventional phthalates to alternative plasticizers in their vinyl flooring product... 

Plasticizer efficiency n. (1) The parts by weight of plasticizer per 100 parts of resin (phr) required to produce a plasticized PVC resin of a particular hardness on the Durometer A scale. (2) Taking dioctyl phthalate as the industry standard of comparison, one may express the efficiency (in %) of another plasticizer as 100 njni), where n is the phr of DOP required to achieve a particular Durometer value (or other desired property) and ni is the phr of the alternate plasticizer required to reach that same value. 

Smith, Sarah S., Precision Using PET as Recycling Alternative, Plastics News, January 12, 1998, p. 10. 

Typical adhesives in each class are Liquids 1. Solvent—polyester, vinyl, phenolics acrylics, rubbers, epoxies, polyamide 2. Water—acrylics, rubber-casein 3. Anaerobics—cyanoacrylate mastics—rubbers, epoxies hot melts—polyamides, PE, PS, PVA film—epoxies, polyamide, phenolics pressure, sensitive—rubbers. Source Tauernicht, J. O., Bonding and Joining, Weight the Alternatives , Plastics Technology, August 1970. 

Pessaries originally are egg-shaped. Other shapes are available as well. In pharmacy practice often suppository type molds are used. Alternatively plastic pessary molds may be used (strips). The volume of these egg-shaped molds is about equal to a suppository of 2.8 mL. Formerly used metal pessary molds had a volume of 5 mL. In literature the size of pessaries varies weight values between 1.2 and 6.8 g are found [8s]. No studies are available about a desirable volume. For a local effect 2.8 mL seems to be right For a systemic effect a smaller volume is probably adequate. 

On toys, the panel recommended further studies to expand knowledge of the exposure of children, but it took the view that DINP in toys was not harmful for children who use these toys normally. The panel also underscored the need for thorough testing of any alternative plasticizers. 

The process of selection between different plastics can be quite bewildering. Copious information on materials is available from the manufacturers, but traditionally this tends to play down any reference to the defects, and to omit any meaningful comparison with alternative plastics. Nowadays there is a proliferation of databases, offering a facility for computerized selection from an impressive list of materials. Data have been compiled over a very wide range of properties, often with an unbiased presentation and uniform test methods and units. With such a huge bank of data now available, the problem is frequently reduced to being one of deciding which of the abundant properties really matter for the component in hand. 

---