Functionalized Polybutadienes

These additives are mainly used in elastomer applications, where they are suitable for both sulfur and peroxide cures. The effects of both acid content and MW have been reported in Ref. [46]. Property improvements were found to plateau at an average MW of about 10 000 and with about 20% w/w of grafted maleic anhydride. 

Acid-functionalized polybutadienes are most effective with fillers such as calcium carbonate and aluminum and magnesium hydroxides but are not as effective with silicas and other silicates. As with the succinic anhydride derivatives discussed above, it is assumed that the anhydride functional polymers react with the filler surface by 

Maleated polybutadienes have a number of uses, with filler modification being only a minor aspect Synthomer Corporation is one of the main general producers (maleated lithenes), although Evonik markets grades spedally aimed at the use with caldum carbonate fillers (Polyvest). 

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A large number of polymeric compounds have been investigated, but most modem propellants utilize prepolymers that ate hydroxy-functional polybutadienes (HTPB), carboxy-functional polybutadienes (CTPB), or a family of polyethylene oxides (PEGs) to form urethanes. Typical cure reactions... 

Initial reports on chemoenzymatic block copolymer synthesis focus on the enzymatic macroinitiation from chemically obtained hydroxy-functional polymers (route A in Fig. 4). The first report on enzymatic macroinitiation was published by Kumar et ah, who used anionically synthesized hydroxy-functional polybutadiene of various molecular weights ranging from 2600 to 19,000Da (Fig. 5) [16]. In a systematic study, the authors investigated the efficiency of the macroinitiation of CL and PDF by Novozym 435 as a function of the polybutadiene macroinitiator. The reaction profile showed that polybutadiene consumption steadily increased with the reaction... 

Fig. 5 Synthesis of poly(butadiene- -caprolactone) from hydroxy-functional polybutadiene [16]...

We have performed such calculations for samples of non-functional polybutadienes 66) (Fig. 11) and, using the found Ax and X0 values, we calculated Kd0) for a cubic lattice model and a slit-like pore within the whole experimentally accessible eab range using Eq. (3.16). The result presented in Fig. 12 shows a good agreement of the experimental data with the calculated curves. Even such a crude model as the lattice-like model and a slit-like pore can be successfully applied to assess the change in the retention volume as a function of the composition of the mobile phase. 

Figure 12.1 Synthesis of poly(butadiene-b-caprolactone) from hydroxyl functional polybutadiene. The plot shows the consumption of the macroinitiator ( ) and...

Tablell. Various parameters of oo-fimctionalized linear (L) and mono-(lN)-, Di-(2N)-, and tri-(3N)-G>-functionalized polybutadienes.

Plasticized epoxy resins can be produced by reacting low molecular mass epoxy resins with dimeric fatty acids. These resins (e.g., Epikote 872, Shell) generally exhibit better substrate wetting than the unmodified epoxy resins. This reaction is, however, associated with the formation of ester bonds, and the resins therefore have a poor resistance to alkaline solutions. Instead of fatty acids, carboxy-functional polybutadiene-acrylonitrile elastomers can also be used to flexibilize epoxy resins. 

Secondary amine-functionalized polybutadiene with high 1,4-micro structure (1,4-content = 90%) was prepared by normal addition of N-benzylidenemethylamine to PBDLi (Mn = 2300 g mol" ) solutions in cyclohexane solvent. The reactions of PBDLi with N-benzylidenemethylamine were rapid, as evidenced by the appearance of light yellow color as soon as it was added to PBDLi solutions, and the yellow color became intense as the reaction proceeded. 

Aminoxy chain-end-functionalized polybutadienes have been prepared by the reactions of PBDLi with halogen-containing benzyloxyamines. PBDLi (Mn = 990gmor, Mw/Mn=1.04) in heptane was reacted with 2,2,6,6-tetra-methyl-l-(2-bromo-l-phenylethoxy)piperidine at -78 °C as shown in eqn [33]. When this reaction was effected at room temperature, 73% of a dimeric polybutadiene product was obtained no dimeric product was observed when the reaction was carried out at -78 °C. The H NMR... 

Kobatake, S., et al. (1998). Block copolymer synthesis by stjrene pol5unerization initiated with nitroxy-functionalized polybutadiene. Macromolecules, 3/(11) 3735-3739. 

These procedures have also been applied to the synthesis of 1,1-dipheny-lethylene-functionalized polybutadiene macromonomers (79) [208, 209]. The general reaction scheme is shown in Eq. (45) ... 

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