Polyesteramide copolymers

PAs have also been copolymerized with other polymer systems and, in particular", with polyesters and poly ethers. In the copoly esteramides the crystallinity is decreased by copolymerization, as the crystalline structure of the amide unit is very different from the ester unit. However, alternating polyesteramides behave as homopolymers with a glass ttansition temperature and a melting temperature intermediate to the polyester and the PA polymer (Figs. 3.10 and 3.11).23,24 Polyesters, such as PBT and PET, modified with a small amount of diamide are also copolymers that have a high order.24,73... 

While all previous examples employ enzymatic ROP, there are two reports on block copolymer synthesis employing enzymatic poly condensation. The first one was published by Sharma et al. and describes the synthesis and solid-state properties of polyesteramides with poly(dimethylsiloxane) (PDMS) blocks [21]. The polycondensation was carried out with various ratios of dimethyl adipate. 

Applications for the Stabaxol stabilizers include thermoplastic polyester urethanes, polyesteramide thermoplastic elastomers, castable polyester urethanes, polyester polyols, monofilament PET fibers, polycarbonates, polycarbonate/PETblends, EVA copolymers and poly(caprolactones). The thermal stabilization of poly(ethylene sulfide) is also accomplished with 4 % hexamethylenebis(t-butyl)carbodiimide and 2 % diphenylacetylene. Also, alternating carbon monoxide/ethylene copolymers are stabilized using aromatic carbodiimides. ... 

Polyamides and polyesteramides are more recent arrivals to the commercial biodegradable polymer field. Copolymers of either glycine or serine with e-aminocaproic acid are biodegradable. For example, biodegradable polyaspartic acid was synthesized (95% yield) at low cost [Koskan, 1992]. A copolymer of butylene-adipate and e-caprolactam was recently introduced by Bayer as BAK 1095. The material has T = 125°C, density of 1070 kg/m, tensile modulus of 180 MPa, maximum strain at break of 400%, tensile stress at break of 25 MPa, and it fully degrades in 300 days under the ASTM standard conditions. 

Such spectra can be used to examine the effects at the molecular level of polymer processing. Thus, Figure 4.9 shows part of the spectra [14] of annealed and quenched forms of a block copolymer of nylon-6 and a polyether-containing polyesteramide (II) with n 9. liie linking unit R is phenylene, and represents a polyether component with both ethene oxide and propane oxide... 

Figure 4.9 Resolution-enhanced 50.3 MHz CP/HPHD/MAS spectra of a nylon-6/20% (polyether/polyesteramide) (II) copolymer (CHj nylon signals only) [14] A, annealed sample B, quenched sample...

Figure 4.14 60 MHz free induction decays for A, nylon-6 and B, copolymer of nylon-6 and 20% polyether/polyesteramide II (see the text) [14], The ordinate is signal intensity on an arbitrary scale...

Figure 4.15. Cross-polarisation dynamics for S0.3MHz spectra of a copolymer of nylon-6 and 40% polyether/polyesteramide (see the text) [14] variation of peak height S with contact time CT A, nylon-6-carbons (diamonds indicate the C4/CS peak, squares are for C2, and circles are for Cl, see III) B, polyether carbons (the symbols are for the peaks at the following chemical shifts triangles 18.2 ppm, circles 75.8 ppm, squares 73.9 ppm, diamonds 71.2 ppm). S is expressed relative to the peak height of the most intense signal, extrapolated to zero CT. A theoretical curve is shown for Cl in A...

The relative amounts of amide and ester units in the polymer chain strongly influenced the physical properties of the polyesteramides. Presence of high content of DBA-O A units resulted in hard solid materials containing a well-developed high melting POA-type crystal phase. Indeed, a melting temperature was observed at around 67°C, which depended on the copolymer composition. When DEA-SiAA units were the major component, the material exhibited a sticky appearance. 

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