Butadiene-acrylonitrile copolymers, liquid

To control compatibility and other properties of butadiene/acrylonitrile copolymers with PVC, there is an optimum acrylonitrile content of 37%. For practical handling, the nitrile rubber is treated on rolls at normal temperatures, and afterwards the mixture is rolled with PVC at elevated temperatures. The reverse process—plasticizing PVC first and mixing with nitrile rubber afterwards—is not so favorable because discoloring and decomposition may occur. This can be avoided by simultaneously applying the liquid plasticizers. Nitrile content in-... 

Nevertheless, it would seem reasonable that, in the absence of any liquid plasticizer medium at all, mobility of ionic impurities would be reduced to such a low level that volume resistivity would remain high. For example, it is well known that polyvinyl chloride can be blended with nitrile rubber, such as Goodrich Hycar 1032 butadiene/acrylonitrile copolymer, and such polyblends are quite soft and flexible without the use of any liquid plasticizer at all (Table VII). 

The polyester resin used in this study, MR 13006 (Aristech Corporation), was supplied as a 60-wt% solution in styrene monomer. The epoxy resin, a digly-cidyl ether of bisphenol A (Epon 828), was obtained from Shell Chemical Company. The reactive liquid rubber, an amino-terminated butadiene-acrylonitrile copolymer (ATBN 1300 x 16), was provided by the BFGoodrich Company. The resin was mixed with additional styrene monomer to maintain the ratio of reactive unsaturation in the polyester-to-styrene monomer at 1 to 3. We added 1.5 wt% of tert-butylperbenzoate initiator to the solution, which we then degassed under vacuum. The mixture was poured between vertical, Teflon-coated, aluminum plates and cured under atmospheric pressure at 100 °C. In the modified compositions, the rubber was first dissolved in the styrene monomer, and then all the other components were added and the solution cured as described. In all the compositions, the ratio of the amine functions with respect to the epoxy functions was kept at 1 to ensure complete cure of the epoxy. 

Liquids, butadiene-acrylonitrile copolymers (Hycar ATBN or CTBN, B.F. Goodrich)... 

Cured vinyl ester resins are fragile after curing like standard UPRs and thus need flexibilization. The flexibilization of vinyl ester resins is made using the known reactive rubber vinyl-terminated liquid elastomeric butadiene-acrylonitrile copolymer (VTBN) [76]. The macrostructure of the VTBN flex-... 

High molar mass epoxy prepolymers containing rabber dispersions based on carboxyl-terminated butadiene-acrylonitrile copolymer were prepared from initially miscible solution of low molar mass epoxy prepolymers, bisphenol A and carboxyl-terminated NBR. During chain extension inside a twin screw extruder due to epoxy-phenoxy and epoxy-carboxy reactions, a phase separation process occurs. Epoxy-phenoxy and epoxy-carboxy reactions were catalysed by triphenylphosphine. The effect of reaction parameters (temperature, catalyst, reactant stoichiometry) on the reactive extrasion process were analysed. The structure of the prepolymers showed low branching reactions (2-5%). Low molar mass prepolymers had a Newtonian rheological behaviour. Cloud-point temperatures of different reactive liquid butadiene aciylonitrile random copolymer/epoxy resin blends were measured for different rubber concentrations. Rubber... 

Low molecular weight liquid nitrile rubbers with vinyl, carboxyl or mercaptan reactive end groups have been used with acrylic adhesives, epoxide resins and polyesters. Japanese workers have produced interesting butadiene-acrylonitrile alternating copolymers using Ziegler-Natta-type catalysts that are capable of some degree of ciystallisation. 

Effect of Molecular Structure. Table III shows the effects of the molecular structure of the liquid polymer on the fracture energy of toughened systems. The CTIN is a carboxyl terminated isoprene-acrylonitrile copolymer CTBS is a carboxyl terminated butadiene and styrene copolymer, and CTA is a copolymer of ethyl acrylate-butyl acrylate. 

Liquid polymers are useful as tackifiers for rubbers, 72) and acrylic coatings. The most interesting are hydroxytelechelic polybutadienes, especially liquid butadiene-acrylonitrile (85/15) copolymers (trademark CN-15, ARCO). This product, known since 1971 as a tackifier, has the following characteristics viscosity 493 poises at 30 °C, tv[n = 4400, hydroxyl number/chain = 2.5. The incorporation of 5% of CN-15 in ethylene-propylene rubber (EPT Nordel 1070) increases its tack considerably 173) close to that of natural rubber or butyl rubbers (Table 4.1). 

Like impact polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS) are sensitive to oxidation caused by the unsaturation of the elastomeric component. The processes for the manufacture of ABS require the drying (at 100°C-150°C) of powdery polymers that are extremely sensitive to oxidation. Thus, antioxidants have to be added before the coagulation step, normally in emulsified form, although sometimes in solution. The primary antioxidants are frequently sued together with a synergist. Primary anti-oxidants commonly used for ABS are BHT, 2,2 -methylenebis-(4-ethyl or methyl-6-tert-hutyl-phenol), 2,2 -methylenebis-(4-methyl-6-cyclohexyl-phenol), 2,2 -methylenehis-(4-methyl-6-nonyl-phenol), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, and l,l,3-tris-(5-tert-hutyl-4-hydroxy-2-methylphenyl)-butane. Important synergists are tris-(nonyl-phenyl)-phosphite and dilauryl thiodipropionate. These antioxidants are either liquids or show comparatively low melting points, which is an important prerequisite for the formation of stable emulsions. 

Liquid carboxy1-terminated butad iene-acrylonitrile copolymer was prepared in this laboratory (5). The number average molecular weight was 2500 and acrylonitrile content 30 wt %. The butadiene unit was mainly in 1,4-trans structure with 11% 1,2-structure. The carboxyl functionality was about 1.9. This product was designated as E-30. 

Figure 1 Cost-related (specific) flexural strength of major thermoplastics, versus cost-related (specific) thermal tolerance. The unit cost is the market price in US cents (1992) of 1 cm plastics. The thermal tolerance is the temperature difference (AT) over room temperature (AT — T - room T), by which temperature (7 ) the flexural modulus is equal to 1 GPa. Designations, abbreviations WFRP-S, wood fiber reinforced PP (S type) of AECL, Canada (See Table 1) PMMA, polymethylmethacrylate PVC, pol)winyl chloride PS, polystyrene PP, polypropylene UP, unsaturated polyesters PA-GF, glass fiber (35%) reinforced polyamide PHR, phenolic resin EP, epoxy resin ABS, acrylonitrile/butadiene/styrene copolymer UF, urea/formaldehyde LDPE, low density polyethylene PC, polycarbonate POM, polyoxymethylene CAB, cellulose acetate butyrate LCP, liquid crystal polymers PEEK, polyether-etherketone PTFE, polytetrafluorethylene.

In order to improve the internal stress performance even further or to provide toughness for potting and adhesive applications it is advantageous to introduce reactive additives to the basic epoxide compound formulation. One of the most popular additives that has found considerable use in this type of application is a rubber-like liquid copolymer known as carboxyl terminated butadiene/acrylonitrile (CTBN). The generalised molecular structure of this material is ... 

Hycar reactive liquid polymers produced by Goodrich Company are homopolymers of butadiene or copolymers of butadiene and acrylonitrile. The isomer content is largely cis/trans with vinyl (1,2-addition of butadiene) being 25% percent or less. They have reactive groups in both terminal positions of the polymer chain end and, optionally, may have additional reactive groups pendant on the chain. Hycar contains no solvent or other unreactive components. There are three types of reactive functional groups commercially available. They are carhoxyl, acrylate, vinyl, and secondary amine. 

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