Plasticizers with acrylic polymers

Plasticizers can be used with acrylic polymers to produce flexible coatings, caulks, and sealants, sometimes serving a role as a coalescing agent instead of a plasticizer. Most of the common phthalates and... 

Primers for plastics Oxazoline acrylic polymers have good adhesion compatibility to plastics. The reason seems to be the presence of polarity, afiBnity, and interaction caused by oxazoline groups that are a kind of cyclic imino ethers. The carboxyl groups in the polymer react with the oxazoline groups and they can also give the polymers good adhesion to plastics. 

The main plasticizers used are the classical plasticizers (i.e. phthalates such as DOP, DBP and DIDP). Adipates are also suitable as polymeric plasticizers, but are rarely used owing to price reasons and their somewhat lower compatibihty. A special polymeric plasticizer polypropylene glycol alkyl phenyl ether (Plastiht 3060) from BASF, has extremely good compatibihty with acrylate polymers and does not migrate. This product has now proven highly successfirl in a number of appHcations (including pressure sensitive adhesives, acryhc sealants and paints). 

The uniqueness of methyl methacrylate as a plastic component accounts for its industrial use in this capacity, and it far exceeds the combined volume of all of the other methacrylates. In addition to plastics, the various methacrylate polymers also find appHcation in sizable markets as diverse as lubricating oil additives, surface coatings (qv), impregnates, adhesives (qv), binders, sealers (see Sealants), and floor poHshes. It is impossible to segregate the total methacrylate polymer market because many of the polymers produced are copolymers with acrylates and other monomers. The total 1991 production capacity of methyl methacrylate in the United States was estimated at 585,000 t/yr. The worldwide production in 1991 was estimated at about 1,785,000 t/yr (3). 

In addition to poly(methyl methacrylate) plastics and polyacrylonitrile fibres, acrylic polymers find widespread use. First introduced in 1946, acrylic rubbers have become established as important special purpose rubbers with a useful combination of oil and heat resistance. Acrylic paints have become widely accepted particularly in the car industry whilst very interesting reactive adhesives, including the well-known super-glues are also made from acrylic polymers. 

Despite these early successes in the commercialization of acrylic polymers, no acrylic PSAs were manufactured on a larger scale until many years later. One of the primary reasons for the initial commercial failure of the acrylic PSAs was their lack of cohesive strength. Unlike the higher Tg, plastic-like polymers obtained from monomers like methylmethacrylate, polymers synthesized from alkyl acrylates typically formed sticky, cold-flowing materials with little if any utility. 

Examples where the acrylic polymer may be compounded with tackifiers or plasticizers include ... 

It has been shown that polymers with free phthalic acid groups dissolve much faster and at a lower pH than those esterified with acrylic or methacrylic groups. The presence of plasticizer and the nature of the salts in the dissolution medium influence the dissolution rate [62],... 

The polymerization of alkyl vinyl ethers is of some commercial importance. The homopolymers, which can be obtained only by cationic polymerization, are useful as plasticizers of other polymers, adhesives, and coatings. (The copolymerization of vinyl ethers with acrylates, vinyl acetate, maleic anhydride, and other monomers is achieved by radical polymerization but not the homopolymerizations of alkyl vinyl ethers.)... 

The toughness of brittle polymers, such as rigid PVC, may be improved by the addition of a semicompatible elastomer such as a polyethyl acrylate graft copolymer. Such composites are harder than polymers plasticized with liquid plasticizers. 

Polymaric plasticizars can ba mada by (1) Internal plasticization whoroby a monomor is copolymorizod with on which tends to yield soft polymers by itself (2) Mechanical mixing of a polymerizable monomer with a polymer, followed by polymerization (3) Mechanical blending of two compatible polymers. In many cases It Is necessary to combine the polymeric plasticizer with a liquid plasticizer because the compatibility of polymers with each other is generally limited. From the industrial polymeric plasticizers, especially polyesters of low degree of polymerization and several copolymers of butadiene with acrylonitrile, acrylic add esters and fumaric add esters were studied. These polymeric plasticizers are characterized by good compatibility and improved cold resistance of the final product. 

The application of polymeric plasticizers can be effected by mixing a preformed polymer mechanically with a polymerizable monomer containing the catalyst and subsequent polymerization. But side reactions, like grafting, must be expected. Generally, this method has not found wide application because the resulting products are likely to show poor mechanical properties. Besides, mixing the monomer on the rolls or in the extruder leads to losses by evaporation and causes unpleasant odors. Furthermore, some of the more important monomers, like the acrylates, show poor compatibility with many polymers. For instance, PVC is not sufficiently plasticizable with acrylates. 

Acrylics. There are two principal classes of acrylic sealants latex acrylics and solvent-release actylics. High molecular weight latex acrylic polymers are prepared by emulsion polymerization of alkyl esters of acrylic acid, The emulsion polymers are compounded inlo sealants by adding fillers, plasticizers, freeze-thaw stabilizers, thickeners, and adhesion promoters. As is true of the silicone lalex sealants, die acrylic latex sealants are easy to apply and clean with water. 

Electronic devices can also generate electromagnetic and radio frequency interference waves that can interfere with other electronic devices. These waves must be modulated and leakage to the environment prevented. Plastics, silicones, acrylics, and polyesters (qv) that are filled with conductive fillers, such as silver, nickel, and copper, are used for this application (1). Although nickel-filled polymers are low cost and efficient, these are not preferred because of the carcinogenic nature of nickel powder. 

Ethylene Copolymers. Ethylene copolymers probably are the most important materials in hot-melt formulations. Ethylene-vinyl acetate and ethylene-ethyl acrylate polymers are very versatile and available in a wide range of grades offering different co-monomer contents and viscosities. The melts are stable and compatible with various modifying resins, waxes, extenders, and fillers. Adhesion to many substrates is good—including the polyolefin plastics, which are difficult to bond with most other types of adhesive unless the surfaces are pre-treated. 

PVC can be chlorinated (CPVC) and be alloyed with other polymers like ABS, acrylics, polyurethanes, and nitrile rubbers to improve its impact resistance, heat deflection, and processability. Although these vinyls differ in having literally thousands of varying compositions and properties, there are certain general characteristics that are common to nearly all these plastics. Most materials based on vinyls are inherently TP and heat sealable. The exceptions are the products that have been purposely compounded with TSs or crosslinking agents are used. 

In this paper first results of the solubility and extraction of low molecular weight polymers and plasticizers with supercritical carbon dioxide are presented and compared to the results of phase equilibria measurements. Additionally the formation of sub-micrometer particles during polymerization of acrylic acid and derivatives thereof in scCC are examined and compared with recent works [2], Finally there are some aspects to modification of polymers by absorption of scC02 and reactive components solved therein. 

Lamination of polymer films, both styrene-based and other polymer types, to styrene-based materials can be carried out during the extmsion process for protection or decorative purposes. For example, an acrylic film can be laminated to ABS sheet during extmsion for protection in outdoor appHcations. Multiple extmsion of styrene-based plastics with one or more other plastics has grown rapidly from the mid-1980s to the mid-1990s. 

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