Resin type plasticizer

Plastisol Viscosity and Viscosity Stability. After the primary contribution of the resin type in terms of its particle size and particle size distribution, for a given PVC resin, plastisol viscosity has a secondary dependence on plasticizer viscosity. The lower molecular weight and more linear esters have the lowest viscosity and hence show the lowest plastisol viscosity, ie, plastisol viscosity for a common set of other formulation ingredients... 

Table 4 lists plastics consumed in building and constmction vs total U.S. plastics consumption for 1990. There was more PVC consumed in the building and constmction sector than any other resin type. 

Phenolics are consumed at roughly half the volume of PVC, and all other plastics are consumed in low volume quantities, mosdy in single apphcation niches, unlike workhorse resins such as PVC, phenoHc, urea—melamine, and polyurethane. More expensive engineering resins have a very limited role in the building materials sector except where specific value-added properties for a premium are justified. Except for the potential role of recycled engineering plastics in certain appHcations, the competitive nature of this market and the emphasis placed on end use economics indicates that commodity plastics will continue to dominate in consumption. The apphcation content of each resin type is noted in Table 2. Comparative prices can be seen in Table 5. The most dynamic growth among important sector resins has been seen with phenoHc, acryUc, polyurethane, LLDPE/LDPE, PVC, and polystyrene. 

In general, resins are compatible with a large number of materials (oils, plasticizers, polyethylene waxes, rubbers). Compatibility depends on resin type, molecular weight and its distribution, resin structure and configuration, and finally on application requirements. 

The monomers, catalysts or hardeners, or plasticizers can include chemicals with the potential to irritate the skin, mucous membranes or respiratory tract. Some can promote skin or respiratory sensitization. The range of chemicals in use is extremely wide, so that reference should be made to the Materials Safety Data Sheet for each specific formulation or variation of it identifiable by reference to the supplier s proprietary name and code number. Some common resin types are summarized in Table 5.55. 

So you ll get no neat definition of resins and plastics here. But you ll know to be careful when someone else uses either term. Now, as for polymer, that s defined as a high molecular weight molecule formed by joining, in a repetitive pattern, one or more types of smaller molecules. 

Where the polymer-to-plasticizer attraction is strong, the plasticizer has high compatibility with the resin and is said to be of the primary or solvent type. With polyvinyl chlondc this attraction is furnished particularly well by ester groups. Where the polymer-to-plasticizer attraction is low the plasticizer is of the secondary or nonsolvent type it functions as a spacer between polymer chains but cannot be used alone because of limited compatibility. This is manifested by exudation of the plasticizer from the resin. Secondary plasticizers are often employed to take advantage of other desirable properties which they may impart Where they are used merely to cheapen the formulation, they are usually referred to as extenders. ... 

Thermoplastic A resin or plastic compound that can be repeatedly softened by heating and hardened by cooling. Examples of thermoplastics are acetal, acrylic, chlorinated polyether, fluorocarbons, polyamides (nylons), polycarbonate, polyethylene, polypropylene, polystyrene, some types of polyurethanes, and vinyl resins. 

Polyurethane Elastomers. Linear polyurethane polymers dissolved in ketone solvents provide a very versatile group of adhesives. Good results are obtained without fillers or other ancillary components in the formulation (indeed, the polymers concerned often are not compatible with the modifying resins and plasticizers that have been used for some time in other types of adhesive). 

About 1.1 billion lb of phthalic anhydride are produced annually in the United States. The major uses are in plasticizers, alkyd resins, and unsaturated polyester resins. The plasticizers are esters made by reacting two moles of an alcohol, such as 2-ethylhexanol, with one mole of phthalic anhydride. These plasticizers find major use in vinyl chloride polymers and copolymers. Alkyd resins are a type of polyester resin used in surface coatings. The most rapidly growing end use is in unsaturated polyester resins for reinforced plastics. 

The most common UV absorbers used commercially are hindered amine light stabilizers, which can also function as heat stabilizers in some plastics. Other UV absorbers include benzotriazoles and benzophenones, salicylate esters, cyanoacrylates, malonates and benzilidenes. Factors such as the nature of the resin, type and level of pigments being used, and the presence of crosslinkers and catalysts govern the selection of UV absorber to be used. 

Much better differentiation of plastic waste from general refuse and segregation of the recovered plastic materials according to resin type is obtained by presorting of the waste at the householder level. As already discussed in connection with the properties of mixtures of PVC and poly(vinyl acetate), or polystyrene with rubber, crude mixtures of two or more polymers usually result in degraded properties relative to those achievable from any of the more rigorously segregated component materials. For this reason, for... 

Antioxidants, typified by bisphenol A, can be added to compositions plasticized by "permanent-type" plasticizers of low volatility when marketed for electrical applications. This is another example of an application where both the PVC resin and plasticizer require heat stabilization (43). 

The number and amount of additives incorporated in a resin vary with resin type and application. A polyethylene resin, for instance, may have only an antioxidant incorporated, or a colorant may also be added. A PVC resin may require several plasticizers, a filler, a heat stabilizer, and a colorant. There are many variations, and in most cases, the final resin formulation is considered by the manufacturer to be proprietary information. A confidentiality agreement may be necessary to make certain that the material meets regulatory compliance, unless the supplier can give the end-user sufficient information to make the determination. 

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