End groups amino

BMI was also used as a crosslinking agent for poly(iminoethylene). The Michael addition takes place with the nucleophilic nitrogen of the imino group and the double bonds of the electrophilic BMI. The Michael addition of BMI is now adopted as a crosslinking reaction for polymers with amino end groups [2]. 

The end group of the polymers, photoinitiated with aromatic amine with or without the presence of carbonyl compound BP, has been detected with absorption spectrophotometry and fluororescence spectrophotometry [90]. The spectra showed the presence of tertiary amino end group in the polymers initiated with secondary amine such as NMA and the presence of secondary amino end group in the polymers initiated with primary amine such as aniline. These results show that the amino radicals, formed through the deprotonation of the aminium radical in the active state of the exciplex from the primary or secondary aromatic amine molecule, are responsible for the initiation of the polymerization. 

The polymers initiated by BP amines were found to contain about one amino end group per molecular chain. It is reasonable to consider that the combination of BP and such polymers will initiate further polymerization of vinyl monomers. We investigated the photopolymerization of MMA with BP-PMMA bearing an anilino end group as the initiation system and found an increase of the molecular weight from GPC and viscometrical measurement [91]. This system can also initiate the photopolymerization of AN to form a block copolymer, which was characterized by GPC, elemental analysis, and IR spectra. The mechanism proposed is as follows ... 

Meijer and co-workers also used a divergent dendrimer synthesis to prepare AB diblock structures (Figure 7.13B) in which the polystyrene linear block is used to initiate growth of the polypropylene imine) dendritic block [45], An amino end group had to be introduced in the polystyrene as a core for subsequent growth of the dendritic fragment via an iterative protocol of sequential... 

These dendritic boxes (Figure 13.7) were synthesized by the conjugation of a chiral shell of protected amino acids onto a flexible polypropylene imine) dendrimer with 64 amino end groups. In solution, the shell was highly hydrogen-bonded and dense-packed, displaying a solid-phase behavior, which was indicated by the low NMR relaxation time of the surface groups [11]. 

Stearoyl-terminated PIPAAms (PIPAAm-CigH35) was obtained by the reaction of the primary amino end group of PIPAAm-NH2 with a large excess of acyl chlorides [23]. A block copolymer of PIPAAm and poly(styrene) (PIPAAm-PSt) was obtained by a condensation reaction... 

The living polymers polystyrylUthium and polyisopropenyllithium can be functionalized with 3-(dimethylaminojpropyl chloride in benzene solution (equation 77). The presence of LiCl increases the functionalization yields. The products were analyzed by size exclusion chromatography and titration of the amino end groups . ... 

N-terminal amino acid Amino acid with an amino end group, nucleoside Contains a pentose and base, nucleotide Contains a phosphate, pentose, and base, oligosaccharide Low molecular weight polysaccharide, phenotype The observable, physical characteristics of an organism. 

These tertiary amino end groups give on further reaction acrylonitrile blocks bounded to polysarcosine such block copolymers are much more soluble than pure polyacrylonitrile. 

Basically, the same sulfonated acid dyes which are used to dye wool are also suitable for polyamide (see Sections 4.10.2-4.10.4). In a weekly acidic dye liquor the sulfonate anion of the dye binds to the ammonium cation, formed from the amino end groups of the fiber. Affinity to the fiber can be increased by introducing addi-... 

Polymerization could be envisaged by reaction of the anhydride group with the lactam moiety of the primary reaction product since, however, amino end groups have been found in the polymer, transamida-tion as indicated in the above scheme must also occur. Although this mechanism cannot be eliminated completely from consideration, we do not feel that it plays a significant part in the conversion of the monomer. 

For best fastness to light and washing, nylon 66 is dyed with acid dyes, and nylon dye variants thus are based on manipulation of the level of acid dye uptake. By adding a monobasic acid such as acetic acid to the reaction mix near the end of the polymerization process, the amino end groups are converted to amide groups which have no affinity for acid dyes under normal dyeing conditions. 

This work can be interestingly related to earlier studies of Harada and coworkers, who prepared a polyrotaxane from a poly(ethyleneglycol) polymer bearing amino end groups and a-CDX.43 The stoppering reaction involved... 

An alternative mechanism of the cationic polymerizatimi of lactams was postulated by Bertalan The protonated amino end-group existing in equilibrium with a tetrahedral intermediate 188d) was assumed as the growing species. 

Bifunctional initiators such as bis-(2-glycylaminophenyl) disulfide (GAPDS) and 2 -azo-2,2 -dimethyldipropiono hydrazide (AMPH) have been used [152] to obtain hydrocaibon chain polymeric initiators with amino end groups able to promote the polymerization of amincmcid A-carboxy anhydrides (NCA) (Scheme 47). 

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