Plasticizer
Plasticizers are additives that increase the plasticity or fluidity the material to which they are added, these include plastics, cement, concrete and clay bodies. Although the same compounds are often used for both plastics and concretes, the desired effect is slightly different. The plasticizers for plastics soften the final product increasing its flexibility. Plasticizers for concrete soften the mix before it hardens, increasing its workability, and are usually not intended to affect the properties of the final product after it hardens.
Plasticizers for plastics
Plasticizers for plastics are additive, most commonly phthalates, that give hard plastics like PVC the desired flexibility and durability. They are often based on esters of polycarboxylic acids with linear or branched aliphatic alcohols of moderate chain length. Plasticizers work by embedding themselves between the chains of polymers, spacing them apart (increasing of the "free volume"), and thus significantly lowering the glass transition temperature for the plastic and making it softer. For plastics such as PVC, the more plasticiser added, the lower its cold flex temperature will be. This means that it will be more flexible, though its strength and hardness will decrease as a result of it. Some plasticizers evaporate and tend to concentrate in an enclosed space; the "new car smell" is caused mostly by plasticizers evaporating from the car interior.
Dicarboxylic/tricarboxylic ester-based plasticizers
Phthalate-based plasticizers are used in situations where good resistance to water and oils is required. Some common phthalate plasticizers are:
Bis(2-ethylhexyl) phthalate (DEHP), used in construction materials, food packaging, children toys, medical devices, and cling wrap
Diisononyl phthalate (DINP), found in garden hoses, shoes, toys, and building materials
Bis(n-butyl)phthalate (DnBP, DBP), used for cellulose plastics, food wraps, adhesives, perfumes and also in cosmetics - about a third of nail polishes, glosses, enamels and hardeners contain it, together with some shampoos, sunscreens, skin emollients, and insect repellents
Butyl benzyl phthalate (BBzP) is found in vinyl tiles, traffic cones, food conveyor belts, artificial leather and plastic foams
Diisodecyl phthalate (DIDP), used for insulation of wires and cables, car undercoating, shoes, carpets, pool liners
Di-n-octyl phthalate (DOP or DnOP), used in flooring materials, carpets, notebook covers, and high explosives, such as Semtex. Together with DEHP it was the most common plasticizers, but now is suspected of causing cancer
Diisooctyl phthalate (DIOP), all-purpose plasticizer for polyvinyl chloride, polyvinyl acetate, rubbers, cellulose plastics and polyurethane.
Diethyl phthalate (DEP)
Diisobutyl phthalate (DIBP)
Di-n-hexyl phthalate, used in flooring materials, tool handles and automobile parts
Trimellitates are used in automobile interiors and other applications where resistance to high temperature is required. They have extremely low volatility.
Trimethyl trimellitate (TMTM)
Tri-(2-ethylhexyl) trimellitate (TEHTM-MG)
Tri-(n-octyl,n-decyl) trimellitate (ATM)
Tri-(heptyl,nonyl) trimellitate (LTM)
n-octyl trimellitate (OTM)
Adipate-based plasticizers are used for low-temperature or resistance to ultraviolet light. Some examples are:
Bis(2-ethylhexyl)adipate (DEHA)
Dimethyl adipate (DMAD)
Monomethyl adipate (MMAD)
Dioctyl adipate (DOA)
Sebacate-based plasticiser
Dibutyl sebacate (DBS)
Maleates
Dibutyl maleate (DBM)
Diisobutyl maleate (DIBM)
Other plasticisers
Benzoates
Epoxidized vegetable oils
Sulfonamides
N-ethyl toluene sulfonamide (o/p ETSA), ortho and para isomers
N-(2-hydroxypropyl) benzene sulfonamide (HP BSA)
N-(n-butyl) benzene sulfonamide (BBSA-NBBS)
Organophosphates
Tricresyl phosphate (TCP)
Tributyl phosphate (TBP)
Glycols/polyethers
Triethylene glycol dihexanoate (3G6, 3GH)
Tetraethylene glycol diheptanoate (4G7)
Polymeric plasticizers
Some other chemicals working as plasticizers are nitrobenzene, carbon disulfide and β-naphthyl salicylate. Plasticizers, such as DEHP and DOA, were found to be carcinogens and endocrine disruptors.
Safer plasticizers
Safer plasticizers with better biodegradability and less biochemical effects are being developed. Some such plasticizers are:
Acetylated monoglycerides; these can be used as food additives
Alkyl citrates, used in food packagings, medical products, cosmetics and children toys
Triethyl citrate (TEC)
Acetyl triethyl citrate (ATEC), higher boiling point and lower volatility than TEC
Tributyl citrate (TBC)
Acetyl tributyl citrate (ATBC), compatible with PVC and vinyl chloride copolymers
Trioctyl citrate (TOC), also used for gums and controlled release medicines
Acetyl trioctyl citrate (ATOC), also used for printing ink
Trihexyl citrate (THC), compatible with PVC, also used for controlled release medicines
Acetyl trihexyl citrate (ATHC), compatible with PVC
Butyryl trihexyl citrate (BTHC, trihexyl o-butyryl citrate), compatible with PVC
Trimethyl citrate (TMC), compatible with PVC
Plasticizers for energetic materials
For energetic materials, especially propellants (eg. smokeless powders), plasticizers based on nitrates are frequently employed. Some such plasticizers are:
Nitroglycerine (NG)
Butanetriol trinitrate (BTTN)
Dinitrotoluene (DNT)
Metriol trinitrate (METN)
Diethylene glycol dinitrate (DEGN)
Bis(2,2-dinitropropyl)formal (BDNPF)
Bis(2,2-dinitropropyl)acetal (BDNPA)
2,2,2-Trinitroethyl 2-nitroxyethyl ether (TNEN)
Due to the secondary alcohol groups, NG and BTTN have relatively low thermal stability. METN, DEGN, BDNPF and BDNPA have relatively low energies. NG and DEGN have relatively high vapor pressure.
Plasticizers for concrete production
Superplasticizers are chemical admixtures that can be added to concrete mixtures to improve workability. Strength of concrete is inversely proportional to the amount of water added or water-cement (w/c) ratio. In order to produce stronger concrete, less water is added, which makes the concrete mixture very unworkable and difficult to mix, necessitating the use of plasticizers and superplasticizers.
Superplasticizers are also often used when pozzolanic ash is added to concrete to improve strength. This method of mix proportioning is especially popular when producing high strength concrete and fiber reinforced concrete.
Adding 2% superplasticizer per unit weight of cement is usually sufficient. However, note that most commercially available superplasticizers come dissolved in water, so the extra water added has to be accounted for in mix proportioning. Adding an excessive amount of superplasticizer will result in excessive segregation of concrete and is not advisable. Some studies also show that too much superplasticizer will result in a retarding effect.
Plasticizers are commonly manufactured from lignosulfonates, a by-product from the paper industry. Superplasticizers have generally been manufactured from sulfonated naphthalene formaldehyde or sulfonated melamine formaldehyde, although new generation products based on polycarboxylic ethers are now available. Traditional lignosulfonate based plasticisers and naphthalene and melamine based superplasticisers disperse the flocculated cement particles through a mechanism of electrostatic repulsion (see colloid). In normal plasticisers, the active substances are adsorbed on to the cement particles, giving them a negative charge, which leads to repulsion between particles. Naphthalene and melamine superplasticisers are organic polymers. The long molecules wrap themselves around the cement particles, giving them a highly negative charge so that they repel each other.
Polycarboxylate Ethers (PCE), the new generation of superplasticisers are not only chemically different from the older sulphonated melamine and naphthalene based products but their action mechanism is also different, giving cement dispersion by steric stabilisation, instead of electrostatic repulsion. This form of dispersion is more powerful in its effect and gives improved workability retention to the cementitious mix. Furthermore, the chemical structure of PCE allows for a greater degree of chemical modification than the older generation products, offering a range of performance that can be tailored to meet specific needs.
In ancient times, the Romans used blood as a superplasticizer for their concrete mixes.
Plasticisers can be obtained by your local concrete manufacturerHousehold washing up liquid may also be used as a simple plasticizer.
ORGANO PHOSPHATE ESTERS
Triphenyl Phosphate (T.P.P)
Chemical Name : Triphenyl Phosphate
Uses
Polyester fibers, Poly Carbonate triacetate,
NC, Photographic films, Cellulose acetate,
ethyl cellulose & cellulose acetate butyrate.
Typical properties :
Physical appearance :White flake
Phosphorus content: wt % 9.5
Specific gravity @ 60° C / 60 ° C :1.220
Melting Point °C :48° C
Acidity as phosphoric acid: % 0.003
Applications :
PAC’S TPP ( Triphenyl Phosphate ), a white flake having low iron content, meets the known specification of all major manufacturers of photographic safety film, It is a recognized organophosphorus flame retardant used in films sheetings, mouldings and certain coatings. Others important properties are its toughening ability and extremely low volatility in cellulose acetate and triacetate, its good resistance to extremely low volatility in cellulose Acetate and triacetate its good resistance to moisture, and its lack of odour. In most applications, it is combined with other plasticizers but it can be used as a primary flame retardant plasticizers in cast triacetate film and sheeting. These products are clear, tough and tack free, It also improves dimensional stability and dielectric strength. Other applications are in moulded acetate products and in coating based in nitrocellulose , ethyl cellulose and cellulose acetate butyrate.PAC’ S TPP when used in large proportions is usually combined with a solvent plasticizer to avoid crystallization and a consequent separation, as it is a solid at room temperature. It is more compatible with cellulose triacetate than with secondary cellulose acetate, but can be incorporated in the latter up to about 30 phr without separation. In secondary cellulose acetate, cellulose acetate butyrate, and ethyl cellulose, for film sheeting or moulding material, it is generally combined with other more active plasticizer such as dimethyl phthalate, dimethoxy ethyl phthalate or diethyl phthalate. It can be used alone in cast triacetate film and sheeting, where, as a very approximate guide, the top limit is 35 phr, or less ( 20-25 phr) under severe service conditions. The approximate top limit in melt-extruded sheeting of film is 15 phr of triphenyl phosphate, and injection moulding material it is about 20 phr. Triphenyl phosphate is compatible with cellulose nitrate in amounts up to equal proportions of plasticizer and resin.
Other films and sheetings :
Triphenyl phosphate as a plasticizer toughens cellulose acetate and imparts a good balance of properties in other films and sheeting. A solvent plasticizer is generally used along with triphenyl phosphate will reduce cold flow and improved tensile strength. Impact strength is correspondingly reduced. Ultraviolet-light stability is average. Whereas phthalate plasticizers and triacetin tend to increase the flammability of a cellulose acctate composition, triphenyl phosphate reduces flammability considerably. Cellulose acetate sheeting containing 20 phr or more triphenyl phosphate will not continue to burn when ignited and the flame withdrawnMoulding compostions : Typical moulding applications of triphenyl phosphate are in cellulose acetate, cellulose acetate butyrate, and vinyl copolymer compound which are used in records, vacuum cleaner parts, housings for clocks and appliances, and parts for Christmas tree lighting sets. Triphenyl phosphate is recommended for use in compounds for records based on vinyl chloride-vinyl acetate copolymer for several reasons. Up to 50 % by weight of fillers must be added to the resin to prevent heat distortion, and up to 5 phr triphenyl phosphate is added to wet these fillers. Its wetting actions is possible because it melts at a slightly lower temperature than the resin. It also functions as a surface – active agent in the calendaring process, and as an internal lubricant improving flow characteristics when the records is moulded. As a plasticizer, it controls brittleness in the final product. Its heat stability, low water absorption and low volatility are all advantages over other plasticizer that has been used in these applications.
Benefits :
It is used principally as a non-solvent plasticizer for cellulose acetate films having up to 80% retentivity and giving flexibility and toughness to the films An excellent catalyst/inhibitor/chain terminator for the growing polymer chain for the manufacture of polyester fibre An excellent fire retardant and plasticizer for synthetic resins viz. Phenol formal-dehyde, decorative laminated sheets etc. It is also used in making stencil blanks, dopes films, varnishes, enamels, plastics, lacquers and for impregnating roofing paper
Tricresyl Phosphate (T.C.P.)
Phosphorus Flame Retardant
TCP ( Tricresyl Phosphate ) is a low viscosity synthetic phosphate ester, Tricresyl Phosphate finds uses in wide variety of applications as Flame retardant plasticizer.
Uses
Leather cloth (PVC) : Upholstery, Book binding, Seat covers
Utility articles : Footwear, Raincoats, Handbags, Fiber glass cellulose acetate
Extruded articles : Cables (PVC & rubber), hoses, flexible pipe, coal mining, conveyor belts
Coatings : Nitrocellulose lacquers, phenolic resins, lube oils
Typical properties :
Physical appearance:Clear Liquid
Phosphorus content:wt % 8.4
Specific gravity @ 25° C :1.17±0.01
Boiling Point (decomposes )°C :415° C
Flash Point °C :220°C
Solubility (G/100 g Solvent) :Water Insoluble ,Completely soluble in Toluene, Methyl Ethyl Ketone, Methanol
TCP is recommended for use in plastisols for fabrics coating & other applications where its low, stable viscosity offers improved processing. TCP can give a driver finish to coated fabrics. TCP has high plasticizing efficiency that enables formulator to achieve better flame retardance at lower cost. It can also be used as flame retardant in phenolic laminatesThe use of proper equipment is recommended. Excess exposure to the product should be avioded. Wash thoroughly after handling.
Product should be stored in cool, dry and well ventilated area away from incompatible materials.
Unless stated, shelf life of the product will be 12 months from the date of packing. For additional handling & toxicological information, consult PAC Material safety Data sheet. Triaryl Phosphate (T.A.P.)
Phosphorus Flame RetardantTAP ( Triaryl Phosphate ) is a low viscosity synthetic Triaryl phosphate ester, Triaryl Phosphate finds uses in wide variety of application as Flame retardant plasticizer
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