Chemical syntheses of biodegradable polymers

Polyamides are a subject of enduring interest because of their variety, their complex internal structures, their commercial importance and versatility, and their various chemistries of preparation and of long-term use. The present review introduces these polymers and then discusses the first of the above aspects, namely the variety of the polyamides. Here, together, the full family is presented, classified conveniently according to the types and combinations of monomers from which they are constructed.

Polyamides – Still Strong After Seventy Years†

The food packaging material is expected to provide optimum protective properties so that the product it encloses remains in satisfactory condition for its anticipated shelf life. The packaging tech...

Totally and Partially Biodegradable Polymer Blends Based on Natural and Synthetic Macromolecules: Preparation, Physical Properties, and Potential as Food Packaging Materials

Other than their established short-chain congeners, polycondensates based on long-chain difunctional monomers are often dominated by the long methylene sequences of the repeat units in their solid-state structures and properties. This places them between traditional polycondensates and polyethylenes. The availability of long-chain monomers as a key prerequisite has benefited much from advances in the catalytic conversion of plant oils, via biotechnological and purely chemical approaches, likewise. This has promoted studies of, among others, applications-relevant properties. A comprehensive account is given of long-chain monomer syntheses and the preparation and physical properties, morphologies, mechanical behavior, and degradability of long-chain polyester, polyamides, polyurethanes, polyureas, polyacetals, and polycarbonates.

Long-Chain Aliphatic Polymers To Bridge the Gap between Semicrystalline Polyolefins and Traditional Polycondensates

Polyamides from lactams by centrifugal molding via anionic ring-opening polymerization

Copolyesteramides—IV. Anionic copolymers of ε-caprolactam with ε-caprolactone. Molecular and chain structure

Anionic copolymers of caprolactam with laurolactam (nylon copolymers) II. Crystallisation, glass transitions and tensile properties

Copolyesteramides—I. Anionic copolymers of ω-laurolactam with ϵ-caprolactone

13C NMR spectra of nylon 6/12 copolymers and related model compounds

The polycondensation of methyl N-(12-hydroxydodecanoyl)-ω-aminoalkanoates (HO(CH2)11CONH(CH2)xCOOCH3) has been studied as a source of the alternating polyesteramides [O(CH2)11CONH(CH2)xCO]n, and the properties of the products compared with those of equivalent random copolymers of similar co-unit ratio. Polymerization of the esters with x = 10 and 11 occurred straight-forwardly, giving crystalline products with were distinguishable from the random counterparts by DSC but not by 67 MHz 13C NMR. For x = 5 the reaction was complicated by progressive partial elimination of the amide moiety as 6-hexanolactam and by transamidation leading, for the polymer of highest amide content obtained, to an imperfect structure with ca. 76% of the sub-units in alternating arrangement, the remainder being composed of oligoester and diamide units. This deviation from ideality has been elucidated by a study of the 13C NMR spectra of a wide range of model compounds which has yielded criteria for the recognition of oligomeric iminohexanoyl units, and by the NMR and MS examination of the products of aminolytic degradation. The results explain the multiple signals found in the 13C NMR spectra of the imperfectly alternating polymer (x = 5) and of its random analogues.

Isaac Goodman

Papers

Copolyesteramides—IV. Anionic copolymers of ε-caprolactam with ε-caprolactone. Molecular and chain structure

Anionic copolymers of caprolactam with laurolactam (nylon copolymers) II. Crystallisation, glass transitions and tensile properties

Copolyesteramides—I. Anionic copolymers of ω-laurolactam with ϵ-caprolactone

13C NMR spectra of nylon 6/12 copolymers and related model compounds

Copolyesteramides, 8. A comparison of substantially alternating 12-oxydodecanoyl/ω-iminoalkanoyl polyesteramides with equivalent random copolymers†