Decomposition of Polymer Fibers

The main mechanisms involving side groups are elimination and cyclization reactions. In elimination reactions, the bonds cormecting side groups to the main 

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What are the possible mechanisms of the decomposition of polymer fibers ... 

The effects of decomposition of polymer-derived fibers in long-term service in inert or reducing conditions can be simulated by long-term exposure to such environments at temperatures above the pyrolysis condition. 

Prethermal decomposition of glass fiber-reinforced and virgin polyamide started at 350°C and proceeded with a weight loss of 100% under nitrogen for the umeinforced polymers [36-39]. Predominant decomposition products were cyclopentanone and epsilon-caprolactam. 

Hsu, C.K., Thermal Decomposition Properties of Polymer Fibers , Thermochimica Acta, 392-393,163-167,2002. 

Combination techniques such as microscopy—ftir and pyrolysis—ir have helped solve some particularly difficult separations and complex identifications. Microscopy—ftir has been used to determine the composition of copolymer fibers (22) polyacrylonitrile, methyl acrylate, and a dye-receptive organic sulfonate trimer have been identified in acryHc fiber. Both normal and grazing angle modes can be used to identify components (23). Pyrolysis—ir has been used to study polymer decomposition (24) and to determine the degree of cross-linking of sulfonated divinylbenzene—styrene copolymer (25) and ethylene or propylene levels and ratios in ethylene—propylene copolymers (26). 

Partially graphitized cokes produced by means of thermal decomposition of organic raw materials, polymers and graphitized carbon fibers show a good performance [1,2,6-17]. The properties of carbon materials are often improved due to large amounts of dopants (H, O, S, N, P, Si, etc.) [9,18],... 

Fluorinated polymers are by nature inert and nontoxic materials. A certain toxicity may however be incorporated from additives added, e.g. perfluorooctanoic acid or traces of monomers. In addition, toxic organo-fluorine compounds may be generated from these polymers by high temperature decomposition.6-64- 16-118 Biological effects of fluorocarbon fibers have been described.119 Toxicities of polychlorotrifluoroethylenc oils (hydraulic fluids) have also been discussed.202... 

Immiscibility of polymers in the melt is a common phenomenon, typically leading to a two-phase random morphology. If the phase separation occurs by a spinodal decomposition process, it is possible to control the kinetics in a manner that leads to multiphase polymeric materials with a variety of co-continuous structures. Common morphologies of polymer blends include droplet, fiber, lamellar (layered) and co-continuous microstructures. The distinguishing feature of co-continuous morphologies is the mutual interpenetration of the two phases and an image analysis technique using TEM has been described for co-continuous evaluation.25... 

Carbon fibers are the most rigid and strongest of commonly used reinforcements. They are produced by the pyrolysis (high-temperature decomposition) of natural and synthetic materials, such as rayon, polyacrylonitrile (PAN), and pitch (the tacky residue left from the distillation of petroleum or coal tar). Carbon fibers are commercially available in a variety of formats, including single strands and bundles (known as tows). They are midway in density between glass and polymer fibers and are the most expensive of commonly used reinforcements. 

Modification of the polymer or the presence of additives can effect the light resistance of a fiber. This is extremely important for textile conservation since fibers being produced currently by the man-made fiber industry may perform differently from those produced in earlier years. For example, a company bulletin, published first in 1960, reported that the resistance to chemical decomposition by fluorescent light or by sunlight of many of the nylons they manufactured had been improved (20). Titanium dioxide, which is used as a delustrant during the manufacture of fibers, can decrease their light resistance (13,15,18, 21, 22, 23). Dyes (18, 24, 25) and finishes (25, 26) are other important factors. 

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