Amination of poly

We have previously reported results of the application of these procedures for the amination of poly(styryl)lithium (11). After an investigation of a variety of procedures, a 92% yield of poly(styryl)-amine was obtained using two equivalents of the amlnating reagent in a THF/Et20/hexane mixture of -78°C followed by slow warming to -15°C and quenching in methanol (eq. 2). 

Fig. 15.3.47. Chloromethylation and amination of poly(styrene-divinylbenzene) resins to form anion exchange resins.

Table 1 Reductive Amination of Poly(vinyl alcohol) ... 

Although benzyllithium has been aminated to 97% yield using these reagents- attempted amination of poly(styryl)lithium (IVI = 2 x 10 ) was achieved with only 5 % efficiency using literature procedures After extensive modification of those procedures, poly(styryl)Iithium has been aminated with 92% efficiency using a twofold excess of methoxyamine/methyllithium . In addition, pure 1 ° amine-terminated polystyrene can be isolated by silica gel chromatography since it is easily separated from the unaminated polymer. 

Hindered amine of poly alky Ipiperidine type (Chimassorb 944) 0.2... 

Other remarkable examples of Qo functionalized amino-polymers are 51 [50], 52 [51] and 53 [52, 53]. The latter was obtained by photochemical reaction between Ca) and the secondary amine of poly (ethylene imine), following a photo-induced electron transfer-proton transfer mechanism. In this way, the authors prepared water-soluble materials with a Ca> content of up to 37 wt%, which showed fluorescence quenching via intrapolymer electron transfer. 

Other fairly recent commercial products, poly(vinyl amine) and poly(vinyl amine vinyl alcohol), have addressed the need for primary amines and their selective reactivity. Prior efforts to synthesize poly(vinyl amine) have been limited because of the difficulty hydrolyzing the intermediate polymers. The current product is prepared from /V-ethenylformamide (20) formed from the reaction of acetaldehyde and formamide. The vinyl amide is polymerized with a free-radical initiator, then hydrolyzed (eq. 7). 

The protonated form of poly(vinyl amine) (PVAm—HCl) has two advantages over many cationic polymers high cationic charge densities are possible and the pendent primary amines have high reactivity. It has been appHed in water treatment, paper making, and textiles (qv). The protonated forms modified with low molecular weight aldehydes are usehil as fines and filler retention agents and are in use with recycled fibers. As with all new products, unexpected appHcations, such as in clear antiperspirants, have been found. It is usehil in many metal complexation appHcations (49). 

Ethyl and butyl esters of poly(vinyl methyl ether)/maleic anhydride (PVM/MA) copolymer were introduced in the early 1960s for use in hair sprays. These polymers also have free carboxy acid groups that can be neutralized. Recommended neutralization is 10%, but products can be found in the range of 5—30%, and recommended neutralizers include ammonium hydroxide, aminomethyl propanol, and triisopropano1 amine. These were the most widely used polymers in hair sprays before their use decreased dramatically in the early 1990s. 

Among the polymeric stabilizers may be listed poly-condensed polymers based on alkyl phenols, aldehydes, and ketones of the aliphatic series, where = 1 - 8 and R,R means alkyl [24], Na, K, Ca phenolates of poly-condensed polymers [25], and also products of epichlor-ide with one or more aliphatic amines C3—C30 [26]. 

Table 8.3 Effect of Amines on Tacticity of Poly(methacrylic acid) at 60 DC90...

The ATPEs have a poly(propylene oxide) backbone widi amine endgroups, as shown in Scheme 4.4. There are several routes to such materials,25 but the only one in current commercial production is die direct amination of polyether polyols. A line of uretiiane-grade ATPEs is made by Huntsman under the tradename Jeffamine. Mono-, di-, and trifunctional products are available in molecular weights up to 5000 g/m. 

An amine-terminated poly ether (ATPE) is prepared as follows. Charge poly(tetramethylene oxide) diol (PolyTHF 1000, BASF, 75.96 g, 0.0759 m) to a 500-mL three-neck round-bottom flask fitted with a thermocouple, a mechanical stirrer, and a vacuum port. Add tert-butylacetoacetate (24.04 g, 0.1582 m) and apply vacuum. Heat at 175° C for 4 h, Fourier transform infrared (FTIR) analysis should indicate complete loss of the polyol OH absorption at 3300 cm. The room temperature viscosity of the product should be about 520 mPa-s. React this acetoacetylated product (85.5 g, 0.0649 m) with cyclohexylamine (14.5 g, 0.1465 m) at 110° C under vacuum for several hours. Cool the resultant cyclohexylaminocrotonate poly ether product to room temperature (1790 mPa-s at room temperature). 

The mechanism of the polymerization of NCA with tertiary amine is still controversial. Mori and Iwatsuki claim that the true initiator is the primary amino group formed by hydrolysis of the NCA with contaminated water and that tertiary amine forms a complex with the NCA and accelerates the addition reaction37 . Harwood et al. confirmed the propagating carbamate by NMR in polymerization initiated with a strong base37 . The successive addition of NCA to the polymer end catalyzed with a strong base affords an alternative procedure for the synthesis of block copolypeptides. Block copolypeptides of poly(oxyethylene) were prepared by triethyl amine catalyzed polymerization of NCA in the presence of poly(oxyethylene)bis-eMoroformate38 . 

Recently siloxane-imide copolymers have received specific attention due to various unique properties displayed by these materials which include fracture toughness, enhanced adhesion, improved dielectric properties, increased solubility, and excellent atomic oxygen resistance 1S3). The first report on the synthesis of poly(siloxane-imides) appeared in 1966, where PMDA (pyromellitic dianhydride) was reacted with an amine-terminated siloxane dimer and subsequently imidized 166>. Two years later, Greber 167) reported the synthesis of a series of poly(siloxane-imide) and poly(siloxane-ester-imide) copolymers using different siloxane backbones. However no physical characterization data were reported. 

An alternative mechanism by which additives may protect polymers from photo-oxidation is radical trapping. Additives which operate by this mechanism are strictly light stabilizers rather than antioxidants. The most common materials in this class are the hindered amines, which are the usual additives for the protection of poly (ethylene) and poly (propylene). The action of these stabilisers is outlined in Reactions 8.3-8.5. 

Hi) Poly amines. In many respects the role of poly amines in plant functioning is still mysterious after many years work. They are almost certainly involved in the control of growth and development through their interactions with nucleic acids and membranes (Smith, 1985). There is increasing circumstantial evidence for their involvement, especially of putrescine, in plant responses to a wide range of stresses including pH, Mg deficiency, osmotic shock, cold, SO2 pollution, and cadmium and ammonium toxicity (Smith, 1985). It remains to be determined, however, how, and indeed whether, putrescine accumulation in response to these diverse stresses is beneficial. 

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