Plasticisers for PVC

Non-ionic surfactants used in detergents, paints, herbicides, pesticides and plastics. Breakdown products, such as nonylphenol and octylphenol, are found in sewage and industrial efffuents Products of combustion of many materials Widely used as plasticisers for PVC. Common environmental pollutants... 

From Table 5.7 it will be seen that plasticisers for PVC such as the octyl phthalates, tritolyl phosphate and dioctyl sebacate have solubility parameters within 1 cgs unit of that of the polymer. Dimethyl phthalate and the paraffinic oils which are not PVC plasticisers fall outside the range. It will be noted that tritolyl phosphate which gels the most rapidly with PVC has the closest solubility parameter to the polymer. The sebacates which gel more slowly but give products which are flexible at lower temperatures than corresponding formulations from tritolyl phosphate have a lower solubility parameter. It is, however, likely that any difference in the effects of phthalate, phosphate and sebacate plasticisers in... 

Many other liquids have been found to be effective plasticisers for PVC but are of limited commercial value, at least in Britain. The effect of plasticisers on the properties of PVC is illustrated in Figure 12.20 (a-e). 

A number of materials exist which are not in themselves plasticisers for PVC because of their very limited compatibility with the polymer, but in conjunction with a true plasticiser a mixture is achieved which has a reasonable compatibility. Commercial extenders, as these materials are called, are cheaper than plasticisers and can often be used to replace up to a third of the plasticiser without serious adverse effects on the properties of the compound. 

The most common plasticisers for PVC are phthalate esters prepared from aliphatic C8 alcohols. For high temperature applications higher molecular weight esters are used, e.g., from mellitic acid, which are resistant to volatilisation and are used for PVC interiors in cars (to prevent fogging of windscreens). 

With regard to the case studies contained in the SubChem project, the effects of the different requirements placed on new substances and existing substances can best be illustrated using the case study of plasticisers for PVC (DINCH as a substitute for DEHP). 

Pilot plant production of PVC resins began in Germany in 1931 followed by the USA in 1933. The beginning of PVC as a technically useful product stemmed from the patent disclosures of Semon of the BF Goodrich Company and Reid of Carbide and Carbon Chemicals in 1933/34. It was discovered that PVC became a flexible material that resembled rubber or leather when it was heated in the presence of a high boiling liquid. This led to the use of phthalate esters as plasticisers for PVC giving a material that was processable at acceptable melt temperatures into products which were permanently soft and flexible. 

Solvating efficiency of the plasticiser for PVC -predicted using Hansen solubility parameters (350) and the Hildebrand solubility parameter (442)... 

Four different polyester plasticisers for PVC, having moderate acid numbers (11.5 to 20.5 mg KOH/g resin), were synthesised. These polyesters were modified by converting the terminal COOH group to Ba(II) and Cd(II) carboxylate salts in order to introduce the capability of heat stabilisation for PVC. The modified polyesters were applied as dual function polyesters, i.e. as plasticisers and stabilisers at the same time. The thermal stabilisation efficiency of the plasticised PVC films formed was tested photometrically and the data obtained were compared with that afforded by Irgastab BZ 556. The efficiencies of these modified polyesters as heat stabilisers for PVC were found to be comparable with those of Irgastab BZ 556. 38 refs. CIBA-GEIGY CO. 

The solvating strength of a plasticiser for PVC is a measure of the interactive forces between these two materials. Hansen s three-dimensional solubility parameters provide a quantitative measure of these... 

ESTER-TYPE PLASTICISERS FOR PVC, BASED ON SOME AROMATIC CONTENT ALCOHOLS. IX. FUNDAMENTAL PARAMETERS IN DEFINING THE ESSENTIAL PLASTICISER PROPERTIES Mirci L E... 

There are also several external plasticisers with almost no proven toxicity, such as, tri-(2-ethylhexyl)trimellitate (TEHTM), di-2-ethylhexyl adipate (DEHA), and acetyl triburyl citrate, (ATBC), which are economically unfeasible for industrial applications, i.e., TEHTM is three times (and for DEHA, four times) as expensive as DEHP. In any case, the use of adipate, mellitate and azoalate type external plasticisers are expected to grow in use at the expense of different phthalate types [19]. Butene based alcohols are also used in the manufacture of flexible PVC [20], whereas polycaprolactone is used as a permanent and safer plasticiser for PVC [21],... 

Details Benzyl butyl phthaiate is mostly used as a plasticiser for PVC (artificial leather, floor tiles and vinyl foams). 

The most prominent application end-uses for PVC blends require permanent plasticisation. Butadiene/acrylonitrile copolymers have been compounded as permanent plasticisers for PVC wire and cable insulation, applications requiring food contact, and in pond liners used for oil containment [21]. Compounding with nitrile rubbers in plasticised PVC provides improved ozone, thermal ageing and chemical resistance for applications such as fuel hose covers, gaskets,... 

Table 6.4 shows some common plasticisers for PVC. The actual reduction in polymer Tg per unit weight of plasticiser is called the plasticiser efficiency. 

Butene-based alcohols have been primarily used in the manufacture of flexible PVC [47], whereas polycaprolactone is applied as permanent plasticiser for PVC [48]. 

Research projects carried out at A F clearly indicate that effective plasticisers for PVC and other resins and binders and additives for alkyd based decorative paints can be based on those raw materials which are the least undisputed from an environmental point of view i.e. renewable resources. These products are not only renewable based but also durable. Provided a positive life cycle analysis, after further R D work plasticisers and high-solid or water borne alkyd paints based on renewables therefore can make an important contribution to a sustainable chemical industry. 

PVC is well known for its efficiency to form miscible systems with various low- or high-molecular-weight polymers, which act as plasticisers. Miscible blends of PVC include its blends with nitrile-butadiene rubber (NBR), chlorinated PE and epoxidised natural rubber (ENR). In PVC/NBR blends, NBR acts as a permanent plasticiser for PVC in applications such as wire and cable insulation, food containers and pond liners. Simultaneously, PVC improves the ozone and chemical resistance as well as thermal ageing characteristics of NBR [a.l04]. 

A primary plasticiser for PVC is regarded as one which is fully compatible with the resin up to at least 100 parts per hundred parts resin (phr) and can be satisfactorily used for many applications as the sole plasticiser. Phthalate and phosphate esters and certain polyesters come into this category. A secondary plasticiser has limited compatibility with PVC, but is normally incorporated in a PVC compound as a partial replacement for a primary plasticiser to impart a specific desirable physical property. Low temperature plasticisers such as sebacates and adipates are typical of this category. Plasticiser extenders are plasticisers of limited efficiency and compatibility such as chlorinated paraffins and certain hydrocarbon oils, which are included in the composition to reduce costs. 

DBP (di-butyl phthalate) was one of the earliest plasticisers for PVC, but is little used today on account of its high volatility. New contenders for large volume use are the phthalates based on straight chain alcohols, of which those based on the Linevol 7-9 and Linevol 9-11 alcohols are typical. They have better low temperature properties and volatility characteristics than their branched chain analogues D79P and DiDP which they otherwise resemble, at the expense of slightly inferior volume resistivity. 

Great Lakes Chemicals Brochure Specialty Plasticisers for PVC. 

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