Phthalate type plasticizers

Analysis of lacquers containing nitrocellulose, alkyd resins, and phthalate-type plasticizers Melamine (2,4,6-triamino-5-triazine) ... 

The polarity of the polyethers makes them incompatible with hydrocarbon-type plasticizers, which tend to bleed. Effective plasticizers are ethers such as di(butoxyethoxyethyl)formal [143-29-3] (Thiokors TP-90B), esters such as di(2-ethylhexyl) phthalate [117-81-7] dioctyl phthalate (DOP), polyesters such as Paraplex G50 (Rohm and Haas), and ether—esters such as di(butoxyethoxyethyl) adipate [114-17-3] (Thiokol s TP-95). The lower mol wt plasticizers, DOP, TP-90B, and TP-95 improve vulcanizate low temperature performance. The polymeric plasticizers maintain higher temperature and long-term aging properties. Epoxidized plasticizers should be avoided because they interfere with vulcanization. 

Primary plasticizers may be further subdivided. The phthalate types me by far the most popular due to cost and ease of incorporation. Dioctyl phthalate and diisooctyl phthalate are typical of this class, They exhibit good general -purpose properties. Phosphate plasticizers are also important for general-purpose use. Typical of these are tritolyl phosphate and trixylenyl phosphate. These plasticizers also impart fire retardant properties. Low-temperature plasticizers, such as dibntyl sebacate, are used where good low-temperature flexibility is required, For maximum... 

Also in the mid seventies, a new type plasticizer - dioctyl terephthalate (DOTP) - was introduced by Eastman. DOTP is less volatile and has better low temperature flexibility than DOP, although it is less solvating than DOP or even DIDP. A branched chain Cg terephthalate is reported to be compatible with PVC but not a 70% linear Cg average phthalate. Most C5 and lower tere-phthalates are reported to be incompatible solids(17). 

Fuel type plasticizers such as phthalates, polyester adipate, or urethane to improve physical and processing characteristics. 

With this background information, it was decided to see how these blends would behave as films. In Table II are tabulated some physical properties of extruded films of PVC/acrylic copolymer blends (9/1, 1/1, and 1/9). In Table III are tabulated physical properties of solution-cast blend films, cast from tetrahydrofuran solution. The cast films contained no lubricants or stabilizers (which were present in the extruded films) nevertheless, their optical property deficiencies were similar to those of the extruded films. The additives used were PVC stabilizer (e.g., organotin compounds), lubricant (e.g., metallic stearates), and plasticizer (phthalate type). 

The majority of plasticizer types discussed in Chapter 2 have been either designed for or used with polyvinylchloride, PVC. But the list of the most common plasticizers changes due to the various circumstances such as the cost of their production, the enviromnetrtal and safety concerns," " " the development of a new group of materials, etc. For example, di-(2-ethylhexyl) phthalate dominated plasticizer use for many decades until recent findings, which questioned its health safety and its readiness to leach out of medical products. The problems with use of the most prominent representative of the phthalate group suddenly changes the stracture of supply and demand. 

Cannot be cut easily with a knife but is relatively easy to scratch, for example, with a knife. This material will dissolve in solvents such as toluene and chloroform but will not dissolve in aliphatic hydrocarbons (paraffin and white spirit). This material will swell in solvents such as alcohols and phenols and is plasticized by some ester-type plasticizers, for example, tritolyl phosphate and dibutyl phthalate. 

A plastisol may be regarded as an organosol in which the continuous phase is almost entirely liquid plasticizer (small amounts of solvent are used for viscosity adjustment). PVC plastisols are made from PVC powder, adipate and phthalate ester plasticizers and minor amounts of epoxy-type resin in solution to aid pigment dispersion and to help (with other additives) to keep the polymer stable to heat and oxidation. The resultant coating is nearly solvent-free and so can be applied in thick films (100-250 m) and stoved without disruption by escaping solvent. The plasticizer penetrates the particles, aiding sintering as the metal substrate reaches c. 200°C in 30-60 s. 

It is useful to note that individual polyurethane elastomer classes are truly compatible with only specific plasticizer classes. Polyether-based urethanes are compatible with phthalate ester plasticizers such as dioctyl-phthalate (DOP) and its analogues, whilst polyester-based urethanes are only compatible with benzoate ester-type plasticizers. 

Temperature is very important on formation of the heterophase system. Even at low concentration of PVC in ester-type plasticizer (for example, in diocfyl phthalate at O 0.1 mol/L) the true solutions are formed only at temperatures above 400 K. Globular structure of suspension PVC and formation of associates retain at temperatures up to 430 - 445 K. In other words, PVC at plasticization, is capable to keep its structural individuality on a supermolecular level, which is formed during polymer s synthesis. Specifically in these conditions the ester-type plasticizer behaves not as a highly-basic solvent, but as a stabilizer at PVC s thermo-degradation due to formation of associates etc. This leads to a reduction of stabilizer s amount, extension of exploitation time of materials and products, etc. 

Other Low-Volatility Monomeric Plasticizers Aside from phthalates, trimellitates, and epoxidized oils, the only other low-volatility monomeric-type plasticizers currently available are shorter-chain fatty acid esters of pentaerythritol (PE) and dipentaerythritol (DPE). The PE ester is in the molecular weight range of the trimellitates and DTDP and thus has comparable volatility to these types of plasticizers. The DPE ester (actually a blend of PE and DPE esters) approaches the higher-molecular-weight range of the epoxidized oils. Both of these products are characterized by low viscosity. 

These products are formulated for optimum cost/performance characteristics for the specific use. The majority of these applications can utilize GP plasticizers such as DINP, DOP, or DOTP. Linear or straight-chain phthalates such as 71 IP-, L9P-, or 61 OP-type plasticizers, are used for improved low-temperature properties and improved oxidation resistance, while DIDP is used for lower volatility and improved diffusion resistance. For improved resistance to migration into nitrocellulose furniture finish, one may choose DOTP or a DIDP/hydrocarbon secondary plasticizer blend. Adipate esters can be used in combination with GP plasticizers to improve low-temperature performance. Plasticizer choices other than these are made only as necessary to provide required performance characteristics. 

These properties are all influenced by the vinyl resin, plasticizer type and concentration, as well as by rheology-control agents (viscosity depressants and thickness). The face fibre are often heat-sensitive (e.g., polypropylene fibers). Therefore the PVC polymers are typically low-molecular-weight vinyl chloride/vinyl acetate copolymers. Plasticizer levels range from 60 to 100 phr. The common practice is to use faster-fusing phthalate DIHP as the sole plasticizer or to use DIHP in dilutions of up to 50 percent with a GP-type plasticizer such as DINP. 

Specialty plasticizers are used in vinyl compositions to provide perfonnance that is beyond that which can be obtained with a general purpose phthalate. These plasticizers can be used by themselves in specific compositions, but are often used in combination with other plasticizers to complement each other s peifoimance. Several major types of specialty plasticizers have been covered in this chapter benzoate esters, polyester polymeries and citrate esters. Each class has specific performance attributes ... 

Aldehydes fiad the most widespread use as chemical iatermediates. The production of acetaldehyde, propionaldehyde, and butyraldehyde as precursors of the corresponding alcohols and acids are examples. The aldehydes of low molecular weight are also condensed in an aldol reaction to form derivatives which are important intermediates for the plasticizer industry (see Plasticizers). As mentioned earlier, 2-ethylhexanol, produced from butyraldehyde, is used in the manufacture of di(2-ethylhexyl) phthalate [117-87-7]. Aldehydes are also used as intermediates for the manufacture of solvents (alcohols and ethers), resins, and dyes. Isobutyraldehyde is used as an intermediate for production of primary solvents and mbber antioxidants (see Antioxidaisits). Fatty aldehydes Cg—used in nearly all perfume types and aromas (see Perfumes). Polymers and copolymers of aldehydes exist and are of commercial significance. 

Uses. Phthabc anhydride is used mainly in plasticizers, unsaturated polyesters, and alkyd resins (qv). PhthaUc plasticizers consume 54% of the phthahc anhydride in the United States (33). The plasticizers (qv) are used mainly with poly(vinyl chloride) to produce flexible sheet such as wallpaper and upholstery fabric from normally rigid polymers. The plasticizers are of two types diesters of the same monohydric alcohol such as dibutyl phthalate, or mixed esters of two monohydric alcohols. The largest-volume plasticizer is di(2-ethylhexyl) phthalate [117-81-7] which is known commercially as dioctyl phthalate (DOP) and is the base to which other plasticizers are compared. The important phthahc acid esters and thek physical properties are Hsted in Table 12. The demand for phthahc acid in plasticizers is naturally tied to the growth of the flexible poly(vinyl chloride) market which is large and has been growing steadily. 

Patents have appeared (33,34) which show formulations containing PMMA emulsion polymer and PMMA suspension polymer combined with benzyl butyl phthalate and octyl benzyl phthalate. It is likely that polymers of this type will require highly polar plasticizers in order to have both adequate compatibiHty and adequate gelation. When replacing PVC appHcations the use of large quantities of phosphate plasticizers is sometimes required to give equivalent fire performance. 

Rubbers. Plasticizers have been used in mbber processing and formulations for many years (8), although phthaHc and adipic esters have found Htde use since cheaper alternatives, eg, heavy petroleum oils, coal tars, and other predominandy hydrocarbon products, are available for many types of mbber. Esters, eg, DOA, DOP, and DOS, can be used with latex mbber to produce large reductions in T. It has been noted (9) that the more polar elastomers such as nitrile mbber and chloroprene are insufficiendy compatible with hydrocarbons and requite a more specialized type of plasticizer, eg, a phthalate or adipate ester. Approximately 50% of nitrile mbber used in Western Europe is plasticized at 10—15 phr (a total of 5000—6000 t/yr), and 25% of chloroprene at ca 10 phr (ca 2000 t/yr) is plasticized. Usage in other elastomers is very low although may increase due to toxicological concerns over polynuclear aromatic compounds (9). 

Vehicles are selected by two methods. In one a concentrate is designed directiy for a resin system, the resin itself, or a compatible resin. Thus when the concentrate is made there is a minimal effect on the properties of the final color. In PVC, often a plasticizer such as dioctyl phthalate (DOP) is used. In the other method, concentrates are made with a commercial universal concentrate vehicle. Concentrate manufacturers and some resin manufacturers have developed vehicles that can incorporate many types of colorants and can be used across many classes of polymers without adversely affecting final product performance. 

Some of the common types of plastics that ate used ate thermoplastics, such as poly(phenylene sulfide) (PPS) (see Polymers containing sulfur), nylons, Hquid crystal polymer (LCP), the polyesters (qv) such as polyesters that ate 30% glass-fiber reinforced, and poly(ethylene terephthalate) (PET), and polyetherimide (PEI) and thermosets such as diaHyl phthalate and phenoHc resins (qv). Because of the wide variety of manufacturing processes and usage requirements, these materials ate available in several variations which have a range of physical properties. 

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