Poly plasticised

In the case of poly(vinyl chloride) plastics, the FWA is mixed dry with the PVC powder before processing or dissolved in the plasticising agent (see Vinyl polymers). Polystyrene, acrylonitrile—butadiene—styrene (ABS), and polyolefin granulates are powdered with FWA prior to extmsion (2,78) (see... 

PVC. Poly(vinyl chloride) (PVC), a very versatile polymer, is manufactured by the polymerisation of vinyl chloride monomer, a gaseous substance obtained from the reaction of ethylene with oxygen and hydrochloric acid. In its most basic form, the resin is a relatively hard material that requites the addition of other compounds, commonly plasticisers and stabilisers as well as certain other ingredients, to produce the desired physical properties for roofing use. The membranes come in both reinforced and nonreinforced constmctions, but since the 1980s the direction has been toward offering only reinforced membranes. The membrane thickness typically mns from 0.8—1.5 mm and widths typically in the range of 1.5—4.6 m. 

Comparison of Table 5.4 and 5.7 allows the prediction that aromatic oils will be plasticisers for natural rubber, that dibutyl phthalate will plasticise poly(methyl methacrylate), that tritolyl phosphate will plasticise nitrile rubbers, that dibenzyl ether will plasticise poly(vinylidene chloride) and that dimethyl phthalate will plasticise cellulose diacetate. These predictions are found to be correct. What is not predictable is that camphor should be an effective plasticiser for cellulose nitrate. It would seem that this crystalline material, which has to be dispersed into the polymer with the aid of liquids such as ethyl alcohol, is only compatible with the polymer because of some specific interaction between the carbonyl group present in the camphor with some group in the cellulose nitrate. 

Today plasticisers are used in a variety of polymers such as polyvinyl acetate, acrylic polymers, cellulose acetate and, most important of all, poly(vinyl chloride). 

Poly(vinyl chloride) has a good resistance to hydrocarbons but some plasticisers, particularly the less polar ones such as dibutyl sebacate, are extracted by materials such as iso-octane. The polymer is also resistant to most aqueous solutions, including those of alkalis and dilute mineral acids. Below the second order transition temperature, poly(vinyl chloride) compounds are reasonably good electrical insulators over a wide range of frequencies but above the second order transition temperature their value as an insulator is limited to low-frequency applications. The more plasticiser present, the lower the volume resistivity. 

In addition to its water solubility poly(vinyl pyrrolidone) is soluble in a very wide range of materials, including aliphatic halogenated hydrocarbons (methylene dichloride, chloroform), many monohydric and polyhdric alcohols (methanol, ethanol, ethylene glycol), some ketones (acetyl acetone) and lactones (a-butyrolactone), lower aliphatic acids (glacial acetic acid) and the nitro-paraffins. The polymer is also compatible with a wide range of other synthetic polymers, with gums and with plasticisers. 

In the late 1970s several developments occurred causing renewed interest in poly(ethylene terephthalate) as a plastics material. These included the development of a new mouldable grade by ICI (Melinar) and the development of a blow moulding technique to produce biaxially oriented PET bottles. In addition there appeared a glass-fibre filled, ionomer nucleated, dibenzoate plasticised material by Du Pont (Rynite) (see Chapter 26). 

Polyesters are eneountered in many forms. They are important as laminating resins, moulding compositions, fibres, films, surface coating resins, rubbers and plasticisers. The common factor in these widely different materials is that they all contain a number of ester linkages in the main chain. (There are also a number of polymers such as poly(vinyl acetate) which contain a number of ester groups in side chains but these are not generally considered within the term polyester resins.)... 

Low molecular weight liquid polyester resins are useful as plasticisers, particularly for PVC, where they are less volatile and have greater resistance to extraction by water than monomeric plasticisers. Examples of such plasticisers are polyfpropylene adipate) and poly(propylene sebacate). In some cases monobasic acids such as lauric acid are used to control the molecular weight. 

Compared with the phenolics and polyesters the resins have better heat resistance, better chemical resistance, particularly to alkalis, greater hardness and better water resistance. In these respects they are similar to, and often slightly superior to, the epoxide resins. Unlike the epoxides they have a poor adhesion to wood and metal, this being somewhat improved by incorporating plasticisers such as poly(vinyl acetate) and poly(vinyl formal) but with a consequent reduction in chemical resistance. The cured resins are black in colour. 

Plasticiser/oil in rubber is usually determined by solvent extraction (ISO 1407) and FTIR identification [57] TGA can usually provide good quantifications of plasticiser contents. Antidegradants in rubber compounds may be determined by HS-GC-MS for volatile species (e.g. BHT, IPPD), but usually solvent extraction is required, followed by GC-MS, HPLC, UV or DP-MS analysis. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out. The determination of antioxidants in rubbers by means of HPLC and TLC has been reviewed [58], The TLC technique for antidegradants in rubbers is described in ASTM D 3156 and ISO 4645.2 (1984). Direct probe EIMS was also used to analyse antioxidants (hindered phenols and aromatic amines) in rubber extracts [59]. ISO 11089 (1997) deals with the determination of /V-phenyl-/9-naphthylamine and poly-2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ) as well as other generic types of antiozonants such as IV-alkyl-AL-phenyl-p-phenylenediamines (e.g. IPPD and 6PPD) and A-aryl-AL-aryl-p-phenylenediamines (e.g. DPPD), by means of HPLC. 

Polymeric plasticisers have been used as partial or total replacements for di(2-ethylhexyl)adipate (DEHA) in PVC cling film to reduce levels of plasticiser migration when used for food contact. Castle et al. [792] used SEC in combination with H 1-NMR and MS for the isolation and identification of seven individual oligomers in the most commonly employed polymeric plasticiser, poly(butylene adipate) (Reoplex R346). Both mass (RI) and specific ester moiety (UV) were being monitored (Figure 4.21). The oligomers were identified... 

Many common polymers, polymeric additives and lubricants oxidise so rapidly after impact in liquid oxygen that they are hazardous. Of those tested, only acrylonitrile-butadiene, poly(cyanoethylsiloxane), poly(dimethylsiloxane) and polystyrene exploded after impact of 6.8-95 J intensity (5-70 ft.lbf). All plasticisers (except dibutyl sebacate) and antioxidants examined were very reactive. A theoretical treatment of rates of energy absorption and transfer is included [1], Previously, many resins and lubricants had been examined similarly, and 35 were found acceptable in liquid oxygen systems [2],... 

Conversely, cling film (plasticised PVC/PVDC, (poly(vinyl chloride)/poly (vinylidene chloride), copolymer, which has very high gas-barrier properties) on peeling from a roll generates static electricity thus promoting adhesion to a surface, e.g., ceramics, but not metallic surfaces which conduct the static electricity away... 

More than 90% of all plasticisers are used with PVC, the remainder being used with PVDC, cellulose diacetate, poly(vinyl acetate) (PVAC), nylons, urethanes and acrylates. 

In the example above, a short-chain poly(ethylene glycol) was added to a rigid polyelectrolyte to plasticise the material and thereby increase polymer-solvent motion in the vicinity of mobile ions. This strategy has been widely explored as a means of improving ion transport in electrolytes. 

Carter, E.V. (1988) A new synthesis process for the manufacture of lamellar iron oxides for pigment use in anti corrosive coatings. J. Oil and Colour Chem. Assoc. 5 132-133 Carty, P. White, S. (1999) Flammability studies on plasticised chlorinated poly(vinyl) chloride. Polymer Degradation Stability 63 455-463... 

Carty, P. White, S. Price, D. Lu, L. (1999) Smoke suppression in plasticised chlorinated poly(vinyl) chloride (CPVC). Polymer Degradation Stability 63 465-468 Caruso, F. Susha, A.S. Giersig, M. Moh-wald, H. (1999) Magnetic core-shell particles Preparation of magnetite multilayers in polymer latex microspheres. Adv. Mater. 11 950-952... 

Ion-selective electrodes (ISEs) with sensor membranes based on sensor molecules plus suitable plasticising solvent mediators are best fabricated with such components physically entangled in a thin poly(vinyl chloride) (PVC) membrane. 

The behaviour of an adipic acid-based polymeric plasticiser for poly(vinyl chloride)s, developed to give improved low temperature flexibility, was compared with that of a conventional adipate plasticiser of the same molecular weight. Blends containing 50 phr plasticiser were prepared. The new plasticiser exhibited a similar softening efficiency and permanence whilst improving the glass transition and brittle temperatures (3-4 C lower). The dry blend time was reduced by 10%. The viscosity of the new plasticiser was 25% lower than that of comparable conventional adipates. 1 ref. 

PLASTICISER MIGRATION AND STRUCTURAL CHANGES IN AN AGED POLY(VINYL CHLORIDE) COATING... 

---