Butadiene-acrylonitrile copolymer terminated

The good low-temperature properties of the flexibilized epoxy resin systems are due to the increased mobility of the segments from the main relaxation down to the y relaxation. Epoxy resin pol3nners modified with Empol(dimerized fatty acid) or Hycar (butadiene-acrylonitril copolymer, terminated by carboxyl groups) show notable strength, impact resistance, and temperature-shock resistance down to 20 Yet none of these systems is ductile... 

Low molecular weight polybutadiene and butadiene-acrylonitrile copolymers terminated with carboxyl, vinyl, amine, epoxy, phenol, and hydroxyl groups have been widely used as toughening agents both for epoxy and polyester resins. Thermally reactive isoprene-acrylonitrile and ethylacrylate-butylacrylate copolymers have also been used [82,83]. 

Studies of the particle—epoxy interface and particle composition have been helphil in understanding the mbber-particle formation in epoxy resins (306). Based on extensive dynamic mechanical studies of epoxy resin cure, a mechanism was proposed for the development of a heterophase morphology in mbber-modifted epoxy resins (307). Other functionalized mbbers, such as amine-terminated butadiene—acrylonitrile copolymers (308) and -butyl acrylate—acryhc acid copolymers (309), have been used for toughening epoxy resins. 

Piperidine and carboxyl terminated butadiene acrylonitrile copolymer (CTBN) at 75 °C. 

Rubber was a carboxyl-terminated butadiene-acrylonitrile copolymer. Mean diameter of rubber particles =1.6 pm. Rubber concentration was 15 phr, giving volume fraction of 0.18 4 Containing vf (glass) = 0.1 rubber = 15 phr... 

It is obvious from these data that CTBN (the carboxyl terminated butadiene-acrylonitrile copolymer) is the most effective modifier, and therefore it was selected for further study. As the concentration of the elastomer was increased to levels up to 100 parts, the impact also increased. The data in Table II show that the room temperature impact of ERL-4221 increased from 40 inch-lbs to greater than 320 inch-lbs by adding 100 phr or 33 wt % of CTBN. At very low temperatures ( —160°F) the impact of the system modified with 60 parts, or 23 wt %, of CTBN was 120 inch-lbs. These impact improvements appear to be directly proportional to the concentration of the elastomer modifier. 

Effect of Molecular Configuration of Elastomer. The extent of the impact and strength improvements of ERL-4221 depends on the chemical structure and composition of the elastomer modifier. The data shown in Table I indicate that the carboxyl terminated 80-20 butadiene-acrylonitrile copolymer (CTBN) is the most effective toughening and reinforcing agent. The mercaptan terminated copolymer (MTBN) is considerably less effective as far as tensile strength and heat distortion temperature are concerned. The mercaptan groups are considerably less reactive with epoxides than carboxyls (4), and this difference in the rate of reaction may influence the extent of the epoxy-elastomer copolymerization and therefore the precipitation of the rubber as distinct particles. 

Carboxyl-terminated butadiene-acrylonitrile copolymer, mentioned above, was found to have 4-cyanopentanoic acid end-group originating from 4,4,7-azobis(4-cyanopentanoic acid) initiator [32],... 

The separate phases will be rich in one component but may have the other present as a minor component. In order to control compatibility the elastomer may have reactive end groups to enhance interfacial adhesion. A common example in epoxy-resin technology is the carboxy-terminated butadiene-acrylonitrile copolymer (CTBN). The structure is shown in Scheme 1.47. In this resin the solubility in the epoxy resin is conferred by the acrylonitrile group, and an increase in the fraction present decreases the upper critical solution temperature, with 26% acrylonitrile conferring total miscibility of CTBN with a DGEBA-based epoxy resin (Pascault et al, 2002). 

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. 

The oil resistance and chemical resistance of nitrile rubber is generally superior to that of EPDM rubbers. However, the highly polar nature of acrylonitrile comonomer is responsible for the high incompatibility between nitrile rubber and polypropylene. The dispersability and the stability of nitrile rubber dispersions in the polypropylene matrix are poor. Hence a reactive compatibilization technology was used [Coran and Patel, 1983], It consisted of blending a small amount of a low molecular weight amine-terminated butadiene-acrylonitrile copolymer (ATBN,... 

Epoxy toughening additives initially were based on rubbery inclusions or functionalized oligomers (carboxy or amine terminated butadiene/ acrylonitrile copolymers). More recently, impact modifiers (core-shell type) similar to that commonly employed with PVC have been proposed. For composites, tougher epoxy matrix candidates... 

The incorporation of elastomers into epoxy resins has been an active area of research over the past decade (1-11). The primary reason for this interest has been the improved toughness of the modified materials. We have limited our work to the carboxy-terminated butadiene-acrylonitrile copolymers (CTBN) produced by... 

Dimethacrylates form highly cross-linked and, therefore, brittle polymers. To overcome brittleness, manufacturers often blend dimethacrylates with polyurethanes or other polymers such as low-molecular-weight vinyl-terminated butadiene-acrylonitrile copolymers and chlorosulfonated polyethylene. The modified dimethacrylate systems provide tough adhesives with excellent properties. These can be formulated as two-component adhesives, the catalyst component being added just prior to use or applied separately to the surface to be bonded. One-component systems also have been formulated which can be conveniently cured by ultraviolet radiation. 

Levita et al. [53] incorporated 10 wt% of a rubber composed of core-shell particles (D = 0.2 pm) and an amine-terminated butadiene acrylonitrile copolymer (ATBN) in different proportions in a DGEBA-based epoxy resin cured with piperidine at 120°C for 12h. The core-shell particles were always immiscible in the epoxy resin while the ATBN phase separated during poly-... 

Butadiene-acrylonitrile copolymer carboxylated Butadiene-acrylonilrile copolymer, carboxyl-terminated. See Butadiene-actylonilrile elastomer,... 

Synonyms Acrylonitrile-butadiene copolymer, carboxyl-terminated Butadiene-acrylonitrile copolymer carboxylated Butadiene-acrylonitrile copolymer, carboxyl-terminated Carboxylated butadiene-acrylonitrile copolymer CTBN... 

Carboxylated butadiene-acrylonitrile copolymer. See Butadiene-acrylonitrile elastomer, carboxyl-terminated Carboxylated epoxy resin. See Epoxy resin, carboxylated... 

Carboxylated butadiene-acrylonitrile copolymer. See Butadiene-acrylonitrile elastomer, carboxyl-terminated 1-(2-Carboxylatoethyl)-4,5-dihydro-3-(2-hydroxyethyl)-2-isoheptadecyl-1H-imidazolium. See Sodium isostearoamphopropionate Carboxylic acid C4. See n-Butyric acid Carboxylic acid C5. See 2-Methylbutyric acid n-Valeric acid... 

Tween 81. See Polysorbate 81 Tween 85 Tween 85LM. See Polysorbate 85 Twinkling Star. See Antimony trioxide Two-stage phenolic resin. See Novolac resin Two-stage resin. See Phenolic resin Ty-lon B11. See Sodium sulfite Tylac 037 Tylac 97-422 Tylac 692 Tylac 757 Tylac 820 Tylac 936 Tylac 979-RG Tylac 68009-00 Tylac 68010-00 Tylac 68012-00 Tylac 68013-00 Tylac 68014-00. See Styrene/butadiene polymer Tylac 68060-00. See Acrylonitrile copolymer Tylac 68073-00 Tylac 68074-00 Tylac 68075-00 Tylac 68076-00. See Butadiene-acrylonitrile elastomer, carboxyl-terminated Tylac 68150-00 Tylac 68151-00. See Butadiene/acrylonitrile copolymer Tylac 68152-00. See Styrene/butadiene polymer... 

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