Plasticisers adipates

All PVC plasticisers have a solubility parameter similar to that of PVC. It appears that differences between liquids in their plasticising behaviour is due to differences in the degree of interaction between polymer and plasticiser. Thus such phosphates as tritolyl phosphate, which have a high degree of interaction, gel rapidly with polymer, are more difficult to extract with solvents and give compounds with the highest brittle point. Liquids such as dioctyl adipate, with the lowest interaction with polymer, have the converse effect whilst the phthalates, which are intermediate in their degree of interaction, are the best allround materials. 

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. 

Being slightly crystalline, there are few good solvents, the best known of which are nitrobenzene, cyclohexanone and tetrahydrofuran. When mixed with certain non-volatile solvents such as some phthalates, adipates and phosphates, flexible materials are obtained and which are referred to as plasticised p. v.c. 

MAE has also been used for the extraction of adipate plasticisers from PVC [464]. The efficiency of MAE depends on the kind of solvent, the temperature achieved and the heating time. The final temperature reached depends on the microwave power, number of vessels and irradiation time. Higher recovery values than SEE were reported for both phthalate and adipate. Other reports on microwave-assisted solvent extraction have appeared [465-467]. 

SPE has been applied to phthalate esters (plasticisers in PVC), polar pesticides (agricultural usage) and for other continuous pollution monitoring problems and environmental analyses [272]. For these applications SPE has largely displaced LLE as the preferred technique for the preparation of liquid samples, e.g. EPA method 506 is concerned with the determination of phthalates and adipate esters in drinking water. 

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... 

Plasticisers Monomeric and polymeric phthalate esters, adipate and citrate esters... 

The use of softeners and plasticisers presents a problem. TP90B, thioethers and certain adipates can give low temperature flexibility to -45 °C, but these are volatile at post cure temperatures, and hence their effect is easily lost. 

As well as aiding processing, a major function of plasticisers is to extend the operating temperature range by improving low temperature flexibility. The majority of demand in CR and NBR is satisfied by general purpose phthalate plasticisers di-2-ethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP). However, a wide variety of speciality plasticisers, mainly esters, are marketed within the rubber industry. The majority of these have linear molecular structures giving them better low temperature performance than the phthalates. Examples of such plasticisers are di-2-ethylhexyl adipate (DOA), butyl carbitol adipate, di(butoxyethoxyethyl) adipate (BCA), and di-2-ethylhexyl sebacate (DOS). 

The enforcement in Denmark of EU Directives on food packaging materials is discussed. Enforcement activities considered include studies of total migration from food contact materials, migration from kitchen-and tableware made of melamine plastics and migration of di(2-ethylhexyl)adipate from plasticised PVC films. Activities which need to be undertaken to increase the effectiveness of enforcement activities in the field of migration are described, including development of selfinspection programmes in industry, European network of enforcement, more rapid analysis and provision of information to the consumer. 2 refs. 

Post and co-workers [49] have used TG-FTIR to study the outgassing of a plasticiser (type and amount) from an ethylene-propylene-diene terpolymer (EPDM) compound. Figure 1.6 shows the thermogravimetric decomposition behaviour of the EPDM compound. The plasticiser emerges in the first mass-loss step, which was identified as adipic acid diisobutylester by on-line infrared analysis. 

Adipic acid Nylon 66, esters, polyurethane resins Fibres, resins, plasticisers, solvents, lubricants Niu etal., 2002... 

Adding a plasticising agent such as dioctyl adipate. 

The most common plasticiser used in this application is di-2-ethylhexyl adipate (DEHA), in combination with polymeric plasticisers and epoxidised soya bean oil. 

Plasticisers are added to PVC to achieve flexibility and workability. The flexibility or softness is determined by the type of plasticiser and level used in relation to the PVC (phr). They also operate as an internal lubricant between the PVC molecules. Based on organic esters, e.g., phthalates, adipates, trimellitates, phosphates, etc., addition levels can be as low as 20 phr for semi-rigid to 100 phr for very flexible applications. The effect on the thermal stability significantly depends on the physical state of the PVC-plasticiser system (260). The relative amount of crystalline PVC in PVC/diethylhexyl phthalate has been identified on the basis of a combination of carbon-13 solution and solid state nuclear magnetic resonance (NMR) (361). 

The volatile photodegradation products from model plasticised (dibutyl adipate - DBA) and titanium dioxide (Ti02) pigmented films have been determined with C02 being the main constituent (108). 

For applications requiring high temperature and extraction resistance, polymeric esters are used (88). New polymeric plasticisers are in development (87) including adipate based for improved low temperature properties (103). Plastisols based on propyleneglycol adipate have been examined (198) and the thermal degradation has been determined using dynamic and isothermal thermogravimetric analysis (188). 

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. 

The results are reported of a study of the effects of several plasticisers on the density, elasticity and degree of expansion of foams produced from different PVC plastisols containing either 44 parts of chalk and 52 parts of plasticiser or 60 parts of chalk and 66 parts of plasticiser. Plasticisers employed were di-iso-heptyl phthalate, DOP, butyl benzyl phthalate, dioctyl adipate, dodecyl benzene or combinations thereof. 9 refs. EASTERN EUROPE YUGOSLAVIA... 

Based on low-toxicity polymeric plasticisers, new formulations of PVC plastisols were proposed and characterised. The study used propyleneglycol adipate as the polymeric plasticiser and compared its properties with two conventional phthalates DEHP and DINP. Mechanical and optical properties were examined, together with the determination of the optimum processing conditions for the higher viscosity plastisols using the polymeric plasticiser. 21 refs. 

The rheological properties of pastes of emulsion PVC having k-values of 69,70 and 75 for coating fabrics were investigated using a coaxial viscometer and the influence of the content and type of plasticiser (dioctyl phthalate and dioctyl adipate) on these properties evaluated. Consistency index and power law index values for the various formulations were determined and the results obtained analysed statistically using shear stress as the variable for each paste. 14 refs. 

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