Carboxylated polybutadiene

Polymers can be modified by the introduction of ionic groups [I]. The ionic polymers, also called ionomers, offer great potential in a variety of applications. Ionic rubbers are mostly prepared by metal ion neutralization of acid functionalized rubbers, such as carboxylated styrene-butadiene rubber, carboxylated polybutadiene rubber, and carboxylated nitrile rubber 12-5]. Ionic rubbers under ambient conditions show moderate to high tensile and tear strength and high elongation. The ionic crosslinks are thermolabile and, thus, the materials can be processed just as thermoplastics are processed [6]. 

Sayles (Ref 67) combined n-butylferrocene with l-(2,3-epoxyaliphatic) carboianes of at least 3 carbonations in the aliphatic chain to function both as burning rate catalysts and cross-linking agents for carboxylated polybutadiene and acrylate binders. The use of 1,2-bis(2,3-epoxy-piopyl) carborane and 1-(2,3-epoxypropyl) car-borane boosted the burning rate of a butyl-ferrocene propint from 1.2 to 1.9 inches/sec as the data in Table 32 indicates... 

T.L. Boggs et al, AIAA J 8 (2), 370-72 (1970) CA 72, 113371 (1970) Scanning electron microscopy is used to study the surface structure of solid proplnts, prepd from AP (I) and polyurethane or carboxylated polybutadiene. Polyurethane proplnts are self-extinguish-ing at high pressure due to the flow of molten binder over I crystals. 1 crystals formed a thin surface melt with gas liberation in the molten phase... 

Carboxylated polybutadiene ionomers, which are close relatives of the polyethylene ionomers described above, have an essentially polybutadiene backbone that contains some acrylonitrile and styrene to adjust its flexibility and toughness, and, in addition, up to 6% by weight of acrylic or methacrylic acid. Like the polyethylene ionomers, they are usually made by direct copolymerization with the carboxylic acid monomer using, however, emulsion methods. Typically the monomers are slurried in water with sodium dodecylbenzene sulfonate as the emulsifier and potassium persulfate as the free-radical initiator. The tendency of the carboxyhc add monomer to dissolve in the aqueous phase instead of remaining in the butadiene-rich phase is suppressed by making the aqueous phase acidic so that the monomer remains in the nonionized form. 

Epoxy structural adhesives which employ carboxylic polybutadiene/acrylonitrile solid and liquid (CTBN) elastomers as modifiers have increased in number and proliferated in use since their introduction in the mid- 60 s. Such adhesive systems are now used in aircraft, electronics, automotive and industrial bonding operations. In the mid- 70 s, amine-reactive versions of the liquid polymers (ATBN) were issued, thereby offering another way to introduce rubber modification into a cured epoxy network. References are cited which provide detailed discussions of nitrile rubber, carboxylic nitrile rubber and both carboxyl- and amine-terminated nitrile liquid polymers (1-4). ... 

Both the ground and precipitated calcium carbonates can by treated with stearic acid to control water absorption, improve dispersabUity, and promote better wetting of the flUer by rubber. Silane treatment of these fillers is not effective. However, there is an ultra-fine grade coated with carboxylated polybutadiene, which reactively links to the particle surfaces. Such treated ultra-fine products can give reinforcement of about the same level of the semireinforcing thermal carbon blacks. 

Non-reinforcing fillers such as clay and calcium carbonate may be enhanced with surface treatments such as carboxylated polybutadiene, calcium stearate, or an organo-silane coupling agent. 

Then the a-oj carboxylated polymer, an a-oj carboxylated polybutadiene (HOOC-PB-COOH) of industrial origin kindly provided by Polyplastic (Rueil-Malmaison, France) in our case, is aminated by addition of ethylene diamine in presence of DCCI in toluene solution. ... 

The carboxylated polybutadiene coated sample is seen to give a much lower dye adsorption than the uncoated filler, as would be expected. When subjected to an ultrasonic probe treatment, slurries of both the coated and uncoated fillers show a marked rise in dye adsorption. This is assumed to be due to break up of filler aggregates exposing fresh uncoated surface. Similar results were obtained with a stearate coated filler. Such generation of uncoated surface might also be expected when fillers of this type are subjected to high shear mixing processes. 

Typical isotherms for the adsorption of a carboxylated polybutadiene onto an alumininm and a magnesium hydroxide filler of similar surface areas are presented in Figure 4.3. The isotherms were determined by using infra-red to follow the decrease in solution... 

Precipitated calcium carbonates are produced by controlled precipitation from calcium hydroxide solution by carbonation. The products of these processes are fine particles (0.05-0.2 pm) and are often coated with a fatty acid (stearic) or a reactive resin (carboxylated polybutadiene). Uncoated grades are also available. 

PCC is also surface treated with materials such as carboxylated polybutadiene. In this case the carboxyl groups react with the surface in a similar manner to stearic acid but the double bonds are available for reaction with polymers. The filler can be pre-coated, or the carboxylated polybutadiene can be added separately during compounding. 

Gong LZ, Wool RP, Friend AD, Goranov K Synthesis and characterization of high molecular weight carboxylated polybutadiene. J Polym Sci Pol Chem. 1999 37 3129-3138. 

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