Poly methylene diamines

C. Base-Adducts of (Ph2Si0)g[A10(0H)]4 with Poly-Methylene-Diamines H2N(CH2)nNH2 61... 

Instead of coordinating mono-hapto bases to the protons of (Ph2SiO)8[Al-0(0H)]4, we have explored the field of di-hapto bases like poly methylene diamines as possible donors. As the molecule (Ph2Si0)8[A10(0H)]4 has pairs of hydroxyl groups directed in the same direction a coordination of H2N(CH2) NH2 could either lead to an intramolecular loop or to intermolecular aggregations of molecules. This field of chemistry is actually very much expanding and we give in this review only a small out-look, essentially with the diamines 1,3-diaminopropane, 1,4-diaminobutane and 1,5-diaminopentane. 

The most striking structural element in these 1 2 adducts of (Ph2Si0)8[A10(0H)]4 with poly methylene diamines is the asymmetry in the bonding of the two diamines. In Table II always two pairs of O - N and Al-O distances are given the first pair is taken from one side of the molecule and the second from the opposite side. It is evident that although the two diamines are chemically and structurally identical and... 

Statistical copolymerization of ethylene glycol and 1,4-butanediol with dimethyl ter-ephthalate results in products with improved crystallization and processing rates compared to poly(ethylene terephthalate). Polyarylates (trade names Ardel, Arylon, Durel), copolymers of bisphenol A with iso- and terephthalate units, combine the toughness, clarity, and proce-sibility of polycarbonate with the chemical and heat resistance of poly(ethylene terephthalate). The homopolymer containing only terephthalate units is crystalline, insoluble, sometimes infusible, and difficult to process. The more useful copolymers, containing both tere- and isophthalate units, are amorphous, clear, and easy to process. Polyarylates are used in automotive and appliance hardware and printed-circuit boards. Similar considerations in the copolymerization of iso- and terephthalates with 1,4-cyclohexanedimethanol or hexa-methylene diamine yield clear, amorphous, easy-to-process copolyesters or copolyamides,... 

Figure 10.7 Comparison of the damping peaks of tetraglycidyl methylene diamine and diamino diphenyl sulphone (TGMDA-DDS epoxy network) (O) and poly(bismaleimide) (BMI network) ( ).

A/f-copolymers have a unique situation among macromolecular compounds. They have an ordered structure of the type -[A-B-]n, which can be viewed as the structure of a homopolymer. The fact that a/f-copolymers can be formed from two starting monomers is not their unique property, and many homopolymers formed in step reactions have an -[A-B-]n formula. For example. Nylon 66, being formed from adipic acid and 1,6-hexandiamine, can be considered an a/f-copolymer and named poly(hexamethylene-diamine-a/f-adipic acid), or it can have the name poly(hexamethylene adipamide) or poly(iminohexa-methylene iminoadipoyl) and be viewed as a homopolymer with the structure -[NH-(CH2)6-NHC(0)-(CH2)4-C(O)-]n. Many other examples of the same type can be listed. 

Special terminology based on trade names has been employed for some polymers. Although trade names should be avoided, one must be familiar with those that are firmly established and commonly used. An example of trade-name nomenclature is the use of the name nylon for the polyamides from unsubstituted, nonbranched aliphatic monomers. Two numbers are added onto the word nylon with the first number indicating the number of methylene groups in the diamine portion of the polyamide and the second number the number of carbon atoms in the diacyl portion. Thus poly(hexamethylene adipamide) and polyfhexamethylene sebacamide) are nylon 6,6 and nylon 6,10, respectively. Variants of these names are frequently employed. The literature contains such variations of nylon 6,6 as nylon 66, 66 nylon, nylon 6/6, 6,6 nylon, and 6-6 nylon. Polyamides from single monomers are denoted by a single number to denote the number of carbon atoms in the repeating unit. Poly(e-caprolactam) or poly(6-aminocaproic acid) is nylon 6. 

Figure 8.12 TEM photographs of triblock copolymers dispersed in a DGEBA-diamine epoxy network. The triblock copolymer is polystyrene-b-polybuta-diene-b-poly(methyl methacrylate), and the epoxy hardener is (a) -methylene bis [3-chloro-2,6 diethylaniline], MCDEA, and (b) 4,4 -diamino diphenyl sulfone, DDS. In the case of the epoxy system based on MCDEA, the PMMA block is miscible up to the end of the epoxy reaction. In the case of the epoxy system based on DDS, the PMMA block phase-separates during reaction. (From LMM Library.)... 

Fig. 8. Effect of the number of methylene group (n) in diamine, dihydrazide and poly-anhydride for cured epoxy resins on Tg 41 ...

Polyesters modified with diimidodicarboxylic acids derived from aliphatic diamines and trimellitic anhydride have been patented, like methylene-N,N-bis-trimellitimide, made from hexamethylenetriamine [82], or the 1,4-dimeth-ylaminocyclohexane derivative [83]. The diacid obtained from trimellitimide, made from the anhydride and dry ammonia, complexed with a divalent metal, e.g., Zn, Co and others, is used in the preparation of a poly(ester-imide), described as giving a wire enamel with good flexibility on copper wire [84]. 

The synthesis of polytartaramides was first reported by Minoura and coworkers.79 During the 1970s, Ogata et a .80-81 described the polycondensation of tartaric acid itself or its 2,3-69-methylene derivative with diamines, by a variety of procedures. These authors also studied the copolymerizations of diethyl-L-tartrate with other diesters64 and reported that the rate of polymerization of dimethyl-L-tartrate with 1,6-diaminohexane in dimethyl sulfoxide at 60°C increased when the reactions were conducted in the presence of such polymer matrices as poly (vinyl pyrrolidone), pullulan, and poly (vinyl alcohol). The rate increased with increasing molecular weight of the matrix.82... 

Typically such reactions take place between reactive components, such as dibasic acids with diamines to give polyamides, or dibasic acids with diols to form polyesters. This reaction has an important modification in the case of nylon 6,6 [poly(hexa-methylene adipamide)], where the initial product of reaction between hexamethylenediamine and adipic acid is a salt, which can be recrystallised readily in order to obtain the high-purity intermediate essential for conversion to high molar mass product. The condensation part of the reaction in this case is brought about by heating the intermediate salt. 

In order to exploit the inductive effect of the amide bond on the hydrolysis of the ester linkage in the polymer backbone the amide and ester linkage should be ideally separated by one methylene unit. It was apparent that a hydroxyacetamide structure would yield such an linkage. Hydroxyacetamide amidediols were obtained in high yields as the thermodynamically favorable product upon heating glycolic acid with alkane diamine neat with removal of w ater (Barrows, 1982, 1988, 1994). The polymer is then obtained either by trans esterification polymerization of the diol (bis-hydroxyacetamides) with the desired diester of the diacid or by the reaction of bis-hydroxyacetamides with diacid chlorides (Scheme 3) (Barrows 1982, 1988, 1994). Poly (ester-amides) can be prepared from a wide variety of different bis-hydrox acetamide amidediols and diacids. 

Commonly used chain formers are methacrylamide (MAM), hydroxymethacry-lamide (HMAM), N-vinyl pyrrolidone (NVP), and methoxy poly(ethylene glycol) monomethacrylate (MPEGMA). Sometimes two monomers may be used in combination (e.g., MAM and NVP, or MPEGMA and HMAM). The cross-linkers commonly used are methylene bisacrylamide (MBAM) and poly(ethylene glycol) dimethacrylate (PEGDMA). The free radical initiator used most often is ammonium persulfate (APS) with tetramethylethylene diamine (TEMED) used as a catalyst. 

Polyethylene glycol (PEG) is another well-known molecule used to reduce protein adsorption and/or platelet adhesion. Surface enrichment of a triblock oligomeric PEG containing additive from a polyurethane matrix was reported [54,55]. The authors used PEG as the active groups to suppress protein and platelet adhesion. The authors first synthesized a methylene diphenyl diisocyanate (MDI)-poly (tetramethylene oxide) (PTMO) 1000 prepolymer with a MW of approximately 4750 (PU4750), and then this prepolymer was terminally functionalized with mono amino-polyethylene oxide (PEG) with different MW (PEO550, 2000, or 5000, Table 2.3). This triblock copolymer was mixed with a polyurethane (MDI/ PTMO 1000/ethylene diamine (ED)) at different ratios in dimethylformamide (DMF) and cast into polymer films. The surface compositions of these films were evaluated by XPS. 

A comparison of melting temperatures can also be made between 1,4-CBMA, poly(amides) based onp-xylene-a,a diamine and on p-phenylene bis(ethyl amine) with a series of dicarboxylic acids. The melting points of the poly (amides) based on p-xylene-a,a diamine and on p-phenylene bis(ethyl amine) differ by only about 20-30 °C for polymers whose dicarboxylic acids have the same number of methylene units. The melting temperatures of the trans CBMA s are about 10-15 °C higher than the / -xylene-a,a diamine poly(amides). 

Aromatic amines are solids at room temperature, These hardeners are routinely melted at elevated temperatures and blended with warmed resin. Eutectic mixtures of metaphen-ylene diamine and methylene dianiline exhibit a depressed melting point resulting in an aromatic hardener that remains a liquid over short periods of time. The pot life is considerably longer than that achieved with aliphatic polyamines. Elevated temperature cures are required to develop optimum properties which are maintained at temperatures up to 150°C (300 F). Aromatic amines have improved chemical and thermal resistance when compared to aliphatic poly amines. 

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