Polyacrylate-polymethacrylate-copolymers

Polyacrylate-polymethacrylate copolymers (Eudragits) are widely used as tablet adjuvants and coating polymers [1]. These polyacrylate polymers were also used for the microencapsulation of... 

Plastics that are commonly processed by extrusion include acrylics (polymethacrylates, polyacrylates) and copolymers of acrylonitrile cellulosics (cellulose acetate, propionate, and acetate butyrate) polyethylene (low and high density) polypropylene polystyrene vinyl plastics polycarbonates and nylons. The material properties and extrusion properties have been reviewed by Whelan and Dunning.Additives that may be included to modify or enhance proper-ties include lubricants and antislip agents to assist processing during extrusion plasticizers to achieve softness and flexibility stabilizers and antioxidants to retard or prevent degradation and dyes and pigments. 

Isophorone [14.268], [14.269] is an unsaturated cyclic ketone. It consists of a-isophorone [78-59-1] (3,5,5-trimethyl-2-cyclohexen-l-one), which contains about 1-3% of the isomer P-isophorone [471-01-2] (3,5,5-trimethyl-3-cyclohexen-l-one). Isophorone is a stable, water-white liquid with a mild odor that is miscible in all proportions with organic solvents. It dissolves many natural and synthetic resins and polymers, such as poly(vinyl chloride) and vinyl chloride copolymers, poly(vinyI acetate), polyacrylates, polymethacrylates, polystyrene, chlorinated rubber, alkyd resins, saturated and unsaturated polyesters, epoxy resins, cellulose nitrate, cellulose ethers and esters, damar resin (dewaxed), kauri, waxes, fats, oils, phenol-, melamine-, and urea-formaldehyde resins, as well as plant protection agents. However, isophorone does not dissolve polyethylene, polypropylene, polyamides. 

Butyl acetate [123-86-4] is a colorless, neutral, water-immiscible liquid with a pleasant, fruity odor. It has a good solvency for cellulose nitrate, cellulose ethers, chlorinated rubber, postchlorinated poly(vinyl chloride), poly(vinyl acetate), polyacrylates, polymethacrylates, vinyl chloride copolymers, polystyrene, natural and synthetic resins, alkyd resins, fats, and oils. Cellulose acetate is insoluble. 

Dimethylacetal [534-15-6] (acetaldehyde dimethyl acetal, 1,1-dimethoxyethane) is a neutral liquid that is miscible with water and organic solvents. It dissolves cellulose nitrate, cellulose ethers, poly(vinyl acetate), polyacrylates, polymethacrylates, poly(vinyl ethers), some vinyl chloride copolymers, and synthetic and natural resins. It does not dissolve poly(vinyl chloride), polystyrene, chlorinated rubber, and cellulose acetate. It is used in the production of paints, adhesives, and shoe-cap stiffeners. 

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

It has also been established for the copolymers HEMA-AAm (Fig. 7) that the temperature and intensity of the secondary dispersion do not change systematically with the copolymer composition. Thus, molecular motions underlying the ji or /S dispersions in polymethacrylates or polyacrylates differ from each other. This may be ascribed to a different cooperation of the backbone, but the results obtained so far do not suffice for a more precise interpretation. Likewise, it is difficult to explain156) that PAAc, in contrast to PMAAc, does not exhibit any secondary relaxation above the liquid nitrogen temperature. It is to be noted that the effect of stereoregularity and diluents168) on the /8 relaxation is not easy to estimate because the concomitant decrease in T accounts for the overlapping of the /3 and a transitions. 

With the exception of local main-chain motions, the above-mentioned types of molecular motions have been investigated on a series of hydrophilic polymethacrylates and polyacrylates by means of dynamic mechanical measurements carried out with a torsional pendulum. For this purpose, the constitution of polymethacrylates was systematically altered and correlated with the dynamic mechanical response spectra. It was established for a series of copolymers of poly(2-hydroxyethyl methacrylate) that the temperature of the y relaxation (140 K 1 Hz), assigned to the motion of 2-hydroxyethyl... 

It seems, however, that only polyanions are chiefly concerned in the interferon induction. Further polymers having anionic groups have been investigated besides poly(nucleic acid)s and co-(cyclopolymers) 8, for which a partial hydrolysis of the anhydride moiety is supposed. Thus, poly(vinylsulfonate)s or polyacrylates have been found to be active, but, polymethacrylates inactive. It has been shown that in the case of acrylic acid copolymers the molecular weight is also of importance in addition to the structure of the polymer chain and the fraction of carboxy groups. The influence of these various parameters has been discussed in detail by De Somer (45). 

For coupling to be selective, the chain to be coupled must be end-capped by mutually reacting groups. For example, a living anionic polyacrylate or polymethacrylate can be directly coupled to any polymer or copolymer end-capped by a suitable electrophile. Fladjichristidis and coworkers coupled living anionic PMMA chains with the living PtBuA anion of PS- Zoc -PtBuA by reaction with l,2-bis(bromomethyl)benzene, with formation of a triblock copolymer . ... 

Methods of Separation. Elution Behavior. First, elution was performed by an isocratic elution mode. At a constant column temperature, the copolymers and homopolymers of polymethacrylates and polyacrylates were retained in the column with chloroform (and DCE) without ethanol. Only polystyrene could elute from the column. By adding ethanol to chloroform (and DCE), copolymers with a higher styrene content started to elute, and by increasing the ethanol content in the mobile phase, copolymers with less styrene were eluted. 

Polymethacrylic and polyacrylic acids give essentially no carbon dioxide under these conditions, while polymaleic acid (3ff) evolves 0.2 moles/monomer unit. Copolymers of itaconic and acrylic acid decarboxylate to produce an amount of carbon dioxide roughly corresponding. 

Graft copolymers were prepared by grafting polyfethyleneglycol monomethacrylate) (MPEG) onto polymethacrylate and polyacrylate copolymers via a transesterification reaction, using potassium methoxide as the transesterification catalyst [68]. The composition of the graft copolymers was chosen to lead to water soluble products. IR and XH-NMR spectroscopy and SEC were used to characterize the graft copolymers. 

Preincubation of surfaces with platelet-poor plasma substantially reduced the platelet retention index of polyacrylates and polymethacrylates, but hardly altered the retention index of polystyrene or copolymers with methyl acrylate that are rich in styrene. Even without plasma pretreatment, the surface, when exposed to whole blood, was probably first contacted by molecular elements (including the proteins) before the cellular elements arrived. What then is the mode of action of plasma pretreatment Several hypotheses, none conclusive, can be advanced, such as ... 

Among the carboxylic acid and anhydride functional monomers that have been employed in the synthesis of these thickener polymers are acrylic acid, methacrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, crotonic acid, maleic anhydride, and citraconic anhydride. The copolymers containing maleic and citraconic anhydride monomers are either hydrolyzed or partially esterified to obtain the required carboxyl functionality. Among these carboxylic monomers, maleic anhydride and particularly methacrylic acid are most frequently favored. Carboxylic homopolymers, where they can be formed, might be considered the simplest examples of ASTs were it not for the fact that they are not copolymers as defined, and some are water soluble in their un-ionized states. Examples of carboxylic homopolymers are the un-ionized free-radical-polymerized atactic forms of polyacrylic acid (i) and polymethacrylic acid (2), which are both readily soluble in water. 

Typical suspending agents for the vinyl acetate polymerization are poly(vinyl alcohol) [particularly a grade represented as approximately 88% hydrolyzed poly(vinyl acetate)], gum arabic, hydroxyethyl cellulose, methyl cellulose, starches, sodium polyacrylate or sodium polymethacrylate, gelatin, and an equimolar copolymer of styrene and maleic anhydride neutralized with either sodium hydroxide or aqueous ammonia. Water-insoluble dispersing agents or... 

Polyacrylic acid and polymethacrylic acid, which belong to the same class as pyran copolymer, will protect newborn mice from a lethal infection with vesicular stomatitis virus [137]. Their mode of action in vitro [138] and in vivo [139] has been described. Polyvinyl sulphate will also induce interferon in mice but not in in vitro systems [140]. Some properties of these two compounds have been compared with pyran copolymer [129]. 

Compared to aliphatic hydrocarbons, aromatic hydrocarbons (DIN 51633) have a higher solvency for oils, castor oil, oil-modified alkyd resins, styrene-modfied oils and alkyd resins, saturated polyester resins, polystyrene, poly(vinyl ethers), polyacrylate and polymethacrylate esters. poly(vinyl acetate), vinyl chloride and vinyl acetate copolymers, and many low-polarity resins. 

Isobutyl acetate [110-19-0] is a colorless, neutral liquid with a pleasant, fruity odor. It is miscible with organic solvents, but immiscible with water. Isobutyl acetate has a high solvency for cellulose nitrate, colophony, damar resin, ketone and ketone-formaldehyde resins, maleate resins, urea and melamine resins, and phenolic and alkyd resins. Polymers such as polystyrene, poly(vinyl ethers), poly(vinyl acetate), polyacrylates, chlorinated rubber and vinyl chloride copolymers, as well as fats, greases, and oils are readily dissolved. Postchlorinated poly(vinyl chloride) is less soluble. Polyisobutene, cellulose ethers, polymethacrylates, poly(vinyl butyrals), natural rubber, and manila copal are swollen. Shellac, cellulose acetate, cellulose acetobutyrate, poly(vinyl chloride), and poly(vinyl formal) are insoluble. 

SN > 200 Polyvinylacetate and copolymers polyacrylates and polymethacrylates Polyesters Alkyd resins Cellulose esters... 

Optical texture observations and X-ray investigations showed that the polyacrylate 41 PA 3 and the copolymer 45 (x=0.8) form nematic phases. The polymethacrylate 41 PMA 3 and the copoly ether 45 (x=0.55) display no liquid crystallinity at rest, but exhibit a virtual isotropic liquid-nematic transition a few degrees below Tg, as evidenced by miscibility studies. Copolyether 46 does not show any threaded or schlieren texture, which would be characteristic of a nematic. 

The wide applicability of aluminum porphyrin initiators (1) leads to a variety of tailored block copolymers such as polymethacrylate-polyether and polymethacrylate-polye-ster, as well as polymethacrylate-polymethacrylate and polymethacrylate-polyacrylate, that can be synthesized by sequential living polymerization of the corresponding monomers.- For example, when 1,2-epoxypropane (11, R = Me) is added to a polymerization mixture of methyl methacrylate (21, R = Me) with la at 100% conversion of 21, the polymerization of 11 takes place from the enolate growing end (32 ) to give a narrow MWD polymethacrylate-polyether block copolymer having an alcoholate growing terminal (Table 4). Likewise, the aluminum enolate species (32 ) can also react with lactones (14,15), thereby allowing the formation of a poly(methyl methacrylate)-polyester block copolymer with narrow MWD. 

Sodium DVB/acrylates copolymer Sodium hyaluronate Sodium polyacrylate starch Sodium polymethacrylate Sodium polystyrene sulfonate Sodium PVM/MA/decadiene crosspolymer Sodium styrene/acrylates copolymer Sodium tauride acrylates/acrylic acid/acrylonitrogens copolymer Soluble collagen Starch/acrylates/acrylamide copolymer Starch diethylaminoethyl ether Steareth-10 allyl ether/acrylates copolymer Stearylvinyl ether/MA copolymer ... 

Silica silylate Smectite Sodium acrylate/vinyl alcohol copolymer Sodium bischlorophenyl sulfamine Sodium carbomer Sodium carboxymethyl betaglucan Sodium carrageenan Sodium cellulose sulfate Sodium chloride Sodium hydrosulfite Sodium lauroyl sarcosinate Sodium magnesium fluorosilicate Sodium myristoyl sarcosinate Sodium m-nitrobenzenesulfonate Sodium oieate Sodium palmate Sodium palmitate Sodium polyacrylate Sodium polymethacrylate Sodium polystyrene sulfonate Sodium sarcosinate Sodium silicoaluminate Sodium stannate Sodium stearate Sodium sulfate... 

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