Terminations, polypropylene

Kaneda et al. reported substrate-specific hydrogenation of olefins using the tri-ethoxybenzamide-terminated polypropylene imine) dendrimers (PPI) as nanoreactors encapsulating Pd nanoparticles (mean diameter 2-3 nm) [59]. The catalytic tests were performed in toluene at 30 °C under dihydrogen at atmospheric pressure (Table 9.3). The hydrogenation rates were seen to decrease with increasing generation of dendrimers, from G3 to G5. 

Figure 16.17 Amine-terminated polypropylene imine) dendrimers act as tridentate ligands for the complexation of transition metals [217] (a), and can function as templates for the assembly of Troger s base dizinc(ll) bis-porphyrin molecules, (b) [218]...

Figure 26.3 Intrinsic viscosity of the various nitrile-terminated polypropylene imine) dendrimers in THF as a function of molar mass...

As will be described in Section 5.3, the living polypropylene can be terminated with iodine to give an iodine-bonded monodisperse polypropylene. The analysis of the iodine-terminated polypropylene gives us an information on the structure of the active vanadium-carbon bond because a vanadium is replaced by an iodine atom. The following structure (4) of end groups has been observed in the H NMR spectrum of iodine-terminated polypropylene 98). 

An iodine-terminated polypropylene has been prepared by the reaction of living polypropylene with iodine at — 78 °C l04>. The reaction was complete within a few minutes to yield an almost monodisperse polypropylene (lftw/Mn = 1.15). The elementary analysis of iodine-terminated polypropylene revealed that iodine reacted quantitatively with the vanadium-polymer bond to give a new iodine-polymer bond. 

Burgess et al.I14) found that the living cationic polymerization of THF was initiated with the mixture of isopropyl iodide and AgC104. Therefore, Doi et al.104) have conducted the block copolymerization of polypropylene with THF by using an iodine-terminated polypropylene (4) which was synthesized via the reaction of living polypropylene (3) with I2. Iodine-terminated polypropylene (Kln = 16,500, Klw/Sln = 1.15) was... 

Figure 26 shows a typical GPC elution curve of the ethanol insoluble polymers obtained at 0 °C, (b), together with the GPC curve of the original iodine-terminated polypropylene, (a). Curve b clearly shifted toward higher molecular weights relative to curve a, but retained a narrow molecular weight distribution (Mw/Mn = 1.14), indicative of the formation of a propylene-THF diblock copolymer. The 13C NMR spectrum of the block copolymer is shown in Fig. 27. 

Doi et al. 84) have synthesized a new type of diblock copolymer of propylene and styrene by the coupling reaction between the iodine-terminated polypropylene (4) and monofunctional living polystyrene anion (11) in toluene at 50 °C, as represented by Eq. (47). 

The chemical structures of important amines for curing epoxy resins in adhesive systems are identified in Fig. 5.1. Diethylenetriamine (DETA), triethylenetetramine (TETA), ra-aminoethylpiperazine (AEP), diethylaminopropylamine (DEAPA), ra-phenylenediamine (MPDA), and diaminodiphenyl sulfone (DDS) are the most commonly used members of this class. They are all primary amines. They give room or elevated temperature cure at near stoichiometric ratios. Ethylenediamine is too reactive to be used in most practical adhesive formulations. Polyoxypropyleneamines (amine-terminated polypropylene glycols) impart superior flexibility and adhesion. 

The ene reaction of maleic anhydride with vinylidene-terminated polypropylene that results in a high molecular weight product, (1), and viscosity increase is illustrated below. 

According to a report presented by Fu et al. [180], the influence of POSS-triol on epoxy-amine reaction depends mostly on the magnitude of AT (Tg -Tc) used. Since Tg for epoxy cured with linear aliphatic diamine—2-methyl-1,5-pentadiamine (MPDA)—was higher than the Tg of the same epoxy cured with diamine-terminated polypropylene oxide (PPO), when cured at the same temperature, epoxy-cured MPDA showed a greater improvement in the value of Tg. Moreover, the addition of POSS-triol in tetraglycidyl diamino diphenyl methane (TGDDM) cured with MPDA also increased the rubbery plateau modulus (Fig. 6). 

Polymerization of propylene with vanadium tris(acetylacetonate)-(C2H5)2Cl at low temperature proceeds in a living manner to give a syndiotactic polymer.153 A V-C bond of the living polypropylene end reacts quantitatively with iodine molecule to yield an iodine-polymer bond. The iodine-terminated polypropylenes of low molecular weight (Mn = 630 3200) were found by H and 13C NMR spectroscopy to have a secondary structure at the chain end.154... 

The reaction rates of some common polyols are listed in Table 4.3 where it can be seen that the values of polyesters and polyethers are usually higher than that of simple diols such as 1,4-butane diol. Also when secondary OH groups are introduced into the polyol the reaction rates are reduced, as seen in Table 4.4 where OH-terminated polypropylene glycol is reacted with MDI. The polypropylene glycols of similar molecular weight give reaction... 

As illustrated in Scheme 10.8, the amino group-terminated polypropylene is probably obtained through a special chain transfer mechanism that may involve a dormant species (iii) formed after insertion of the alkylaluminum-treated allylamine. The nitrogen atom of the inserted masked allylamine is located near the Zr cation and results in a stable complex (iii), to which nucleophilic attack from A1(CH3 )3 can occur at the chain end to produce a polymeric intermediate (iv). With HCl treatment during workup, this intermediate (iv) is converted into iPP-NH2 (v). ... 

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