Additives, polymeric

Patent Application Material Patentability Anticipated Issuing Date  

Research Focus Preparation of high-clarity, low-craze polypropylene with improved 

Originality The use of imide additives to reduce haze in polypropylene is 

At ambient temperature a reaction flask charged with cyclohexylamine (240.69 mmol) dissolved in 50 ml of xylene was added to a second flask containing 1,2,4, 5-benzenetetracarboxylic anhydride (229.23 mmol) dissolved in 100 ml of xylene. The reaction was exothermic and a white solid then precipitated out upon mixing. Thereafter, the mixture was stirred at ambient temperature for 2 hours, filtered, and the precipitate washed with xylene. After being dried under vacuum the product was isolated as a white powder. 

Polypropylene blending with amic acid intermediate 

Surface resistivity 1E12 1E12 1E12 1E12 1E12 

Federal Test Method Standard lOlB, Method 4046 Electrostatic dissipation sec. at 50% relative humidity Electrostatic dissipation sec. at 15% relative humidity 

Antistatic compositions are made from poly(ether ester amide) and a thermoplastic resin, functionalized by acrylic acid or maleic anhydride (8). 

ABS resins, and PS, can be rendered antistatic by adding an antistatic blend composed of a copolymer comprising poly(amide) blocks and poly(ether) blocks, sodium perchlorate, and of a fibrous material (9). 

Styrene acrylonitrile copolymers can be rendered to be antistatic by adding a copolymer composed from epichlorohydrin and ethylene oxide and PMMA (7). The mixture is compounded in a Banbury mixer and then injection molded at 220°C. The surface resistivity, the percent of tensile elongation and the electrostatic dissipative rate from 5 kV to 0 V at 15 and 50% relative humidity have been measured. The results are given Table 9.2. 

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Without other alternatives, the carboxyalkyl radicals couple to form dibasic acids HOOC(CH)2 COOH. In addition, the carboxyalkyl radical can be used for other desired radical reactions, eg, hydrogen abstraction, vinyl monomer polymerization, addition of carbon monoxide, etc. The reactions of this radical with chloride and cyanide ions are used to produce amino acids and lactams employed in the manufacture of polyamides, eg, nylon. 

Anionic Polymerization. Addition polymerization may also be initiated and propagated by anions (23—26), eg, in the polymerization of styrene with -butyUithium. The LL gegen ion, held electrostatically in... 

Polymerization Reactions. Polymerization addition reactions are commercially the most important class of reactions for the propylene molecule and are covered in detail elsewhere (see Olefin polymers, polypropylene). Many types of gas- or liquid-phase catalysts are used for this purpose. Most recently, metallocene catalysts have been commercially employed. These latter catalysts requite higher levels of propylene purity. 

Rubber. The mbber industry consumes finely ground metallic selenium and Selenac (selenium diethyl dithiocarbamate, R. T. Vanderbilt). Both are used with natural mbber and styrene—butadiene mbber (SBR) to increase the rate of vulcanization and improve the aging and mechanical properties of sulfudess and low sulfur stocks. Selenac is also used as an accelerator in butyl mbber and as an activator for other types of accelerators, eg, thiazoles (see Rubber chemicals). Selenium compounds are useflil as antioxidants (qv), uv stabilizers, (qv), bonding agents, carbon black activators, and polymerization additives. Selenac improves the adhesion of polyester fibers to mbber. 

Blends of wool and cotton (80 20) are being used more and more. For durable-press properties, resins, catalysts, and polymeric additives in finishing systems must be adjusted (186). 

In addition to acting as impact modifiers a number of polymeric additives may be considered as processing aids. These have similar chemical constitutions to the impact modifiers and include ABS, MBS, chlorinated polyethylene, acrylate-methacrylate copolymers and EVA-PVC grafts. Such materials are more compatible with the PVC and are primarily included to ensure more uniform flow and hence improve surface finish. They may also increase gelation rates. In the case of the compatible MBS polymers they have the special function already mentioned of balancing the refractive indices of the continuous and disperse phases of impact-modified compound. 

An example of this improvement in toughness can be demonstrated by the addition of Vamac B-124, an ethylene/methyl acrylate copolymer from DuPont, to ethyl cyanoacrylate [24-26]. Three model instant adhesive formulations, a control without any polymeric additive (A), a formulation with poly(methyl methacrylate) (PMMA) (B), and a formulation with Vamac B-124 (C), are shown in Table 4. The formulation with PMMA, a thermoplastic which is added to modify viscosity, was included to determine if the addition of any polymer, not only rubbers, could improve the toughness properties of an alkyl cyanoacrylate instant adhesive. To demonstrate an improvement in toughness, the three formulations were tested for impact strength, 180° peel strength, and lapshear adhesive strength on steel specimens, before and after thermal exposure at 121°C. 

Eihyl cyanoacrylate formulations with and without polymeric additives... 

The data also demonstrate that the addition of the thermoplastic, PMMA, does not have the significant effect on the toughness or adhesion properties as does the addition of the rubber, Vamac B-124. Clearly, the physical properties of the polymeric additive determine the magnitude of the adhesive physical property modifications, which result from their addition to an alkyl cyanoacrylate monomer. 

Polyphosphates are also an important class of organophosphorus polymers. In addition to their flame-retardant characteristics, they possess attractive plasticizing properties and can be used as polymeric additives to other polymers [123-128]. In general, polyphosphates can be prepared by interfacial [119,129], melt [130], or solution polycondensation [131,132a,b]. Kricheldorf and Koziel [133] prepared polyphosphates from silylated bisphenols. 

Ishihara K, Tanaka S, Furukawa N, Kurita K, and Nakabayashi N. Improved blood compatibility of segmented polyurethanes by polymeric additives having phospholipid polar groups. I. Molecular design of polymeric additives and their functions. J Biomed Mater Res, 1996, 32(3), 391-399. 

High compatibility of the additive with the polymer matrix usually extends performance but at the expense of extractability. Lack of extractability is of analytical concern, e.g. in case of functionalised oligomer and polymeric additives, grafted and reactive additive functionalities, and chemisorbed and absorbed additives. More generally, additive recovery levels significantly lower than the target level may arise from various situations ... 

Applications Dissolution/reprecipitation is claimed to be the most widespread approach to polymer/additive analysis [603], but recent round-robins cast some doubt on this statement. Dissolution appears to be practised much less than LSEs. However, in cases where exhaustive extraction is difficult, e.g. for polyolefins containing high-MW (polymeric) additives, a dissolution/precipitation method is preferred. 

The most spectacular results with temperature-programmed LC have been obtained for some notoriously difficult polymeric additives. Characterisation of the oligomeric HALS stabiliser poly [[6-[(l,l,3,3-te-tramethylbutyl) amino]-l,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]-l,6-hexanediyl [(2,2,6,6-tetramethyl-4-piperidyl)imino]] (I) (Figure 4.12) is difficult for several reasons it has a broad MWD, may contain isomers, and has several amino groups that promote almost irreversible adsorption to silica based column packings in LC. 

CE has been used for the analysis of anionic surfactants [946,947] and can be considered as complementary to HPLC for the analysis of cationic surfactants with advantages of minimal solvent consumption, higher efficiency, easy cleaning and inexpensive replacement of columns and the ability of fast method development by changing the electrolyte composition. Also the separation of polystyrene sulfonates with polymeric additives by CE has been reported [948]. Moreover, CE has also been used for the analysis of polymeric water treatment additives, such as acrylic acid copolymer flocculants, phosphonates, low-MW acids and inorganic anions. The technique provides for analyst time-savings and has lower detection limits and improved quantification for determination of anionic polymers, compared to HPLC. 

Polymeric additives, polymer-bound (grafted) additives... 

Especially in recent years, there has been a tendency to develop stabilisers with higher-MW (>2000 Da) to prevent loss under severe conditions of application. Polymeric additives for polymers, including impact modifiers, flexibilisers, antistatic agents, and processing aids, have been reviewed [54]. 

Advances in size-exclusion chromatography, coupled with refractive index, absorption, viscosity, and lightscattering detectors, and MALDI-ToFMS, have made it possible to accurately determine molecular weight distribution (oligomer profiling), even at the relatively low values of polymeric additives (up to about 5000 Da). Advances in column design, e.g. high-resolution PS/DVB columns (> 105 plates m-1) mean that SEC can provide a valuable alternative to conventional HPLC techniques for the separation of small molecules. 

Since the depolymerization process is the opposite of the polymerization process, the kinetic treatment of the degradation process is, in general, the opposite of that for polymerization. Additional considerations result from the way in which radicals interact with a polymer chain. In addition to the previously described initiation, propagation, branching and termination steps, and their associated rate constants, the kinetic treatment requires that chain transfer processes be included. To do this, a term is added to the mathematical rate function. This term describes the probability of a transfer event as a function of how likely initiation is. Also, since a polymer s chain length will affect the kinetics of its degradation, a kinetic chain length is also included in the model. 

Acids were an early exception to the no water rule. It was recognized that aqueous solutions of acids would inhibit swelling of clays and shales as well as dissolve any acid-soluble minerals contained in a formation. By 1933 commercial well stimulation with hydrochloric acid was of great interest. A whole separate methodology and treatment chemistry has since evolved around acidizing and fracture acidizing(54). Water emulsions, mainly emulsified acids, and gelled acids thickened with polymeric additives were applied early in the history of well treatment. 

Many common polymers, polymeric additives and lubricants oxidise so rapidly after impact in liquid oxygen that they are hazardous. Of those tested, only acrylonitrile-butadiene, poly(cyanoethylsiloxane), poly(dimethylsiloxane) and polystyrene exploded after impact of 6.8-95 J intensity (5-70 ft.lbf). All plasticisers (except dibutyl sebacate) and antioxidants examined were very reactive. A theoretical treatment of rates of energy absorption and transfer is included [1], Previously, many resins and lubricants had been examined similarly, and 35 were found acceptable in liquid oxygen systems [2],... 

Identification of polymeric additives by their melting point... 

With the introduction of new building technologies, namely application of synthetic polymeric additives, the natural organic additives gradually disappeared [24]. At present, builders are returning to them in particular, biomolecules (saccharides and their derivatives, oils, waxes, etc.) produced by biotechnological procedures have been reintroduced [25]. 

These polymeric additives generally introduce a whole new set of considerations, listed in Table V, which may limit or otherwise affect foam production or use. 

We have recently developed and obtained a patent for an ultra-stabilized high expansion foam (5 ) with expansion and drainage characteristics as shown in Table VI, using a polymeric additive for stabilization without harming expansion. 

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