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Enzymatic and hydrolytic degradation

Special centrifiigaUy spun fibres as an alternative for gel spun fibres were tested regarding hydrolytic degradation (pH 10.6, Fibres degraded [Pg.237]

Although no more detailed studies were found on the environmental degradation of PHB fibres, the above-mentioned effects may be considered to be generally valid for the anisotropic materials depending on the draw ratio, structure parameters (content of a and P phase, etc.). [Pg.238]


Krasowska K., Heimowska A., Rutkowska M. Enzymatic and hydrolytic degradation of poly (e-capTolactone), Intern. Polymer Sci. Technol. 33 (2006) T/57. [Pg.164]

Desizing by chemical decomposition is applicable to starch-based sizes. Since starch and its hydrophilic derivatives are soluble in water, it might be assumed that a simple alkaline rinse with surfactant would be sufficient to effect removal from the fibre. As is also the case with some other size polymers, however, once the starch solution has dried to a film on the fibre surface it is much more difficult to effect rehydration and dissolution. Thus controlled chemical degradation is required to disintegrate and solubilise the size film without damaging the cellulosic fibre. Enzymatic, oxidative and hydrolytic degradation methods can be used. [Pg.101]

Biodegradable polymers are macromolecules mainly derived from renewable sources, which can be enzymatically or hydrolytically degraded into low molecular parts. These parts can be reabsorbed by microorganisms, which ideally convert them to CO2 and water heading to an environmentally closed circular flow economy between growing of nutrients, production, utilization, and material recycling (Fig. 1). [Pg.373]

On the other hand, pores enhance the alkaline and enzymatic surface hydrolytic degradation of aliphatic polyesters because of the increased surface area per unit mass of porous materials compared to that of nonporous materials [307]. Similar to this, the pores formed by the removal of water-soluble polymers such as poly(p-vinyl phenol) from PLLA/ water-soluble polymer blends accelerate the alkaline hydrolytic degradation of PLLA as traced by weight loss [249]. [Pg.371]

Poor degree of conversion of dental resin monomers, elution of un-polymerized monomers and degradation of polymeric chains by enzymatic and hydrolytic challenges, have all been associated with the low stability of the resin at the bonded interface. Novel approaches have focused on improving the adhesion to the dental tissue as well as increasing stability of the resin and resin-dentin interface. [Pg.273]

It has been demonstrated [186] that the inclusion of polyacrylamide in either enzymatic or oxidative desizing formulations results in increased pick-up of the liquor by the sized warp yams. Desizing by hydrolytic degradation of starch during the traditional kier-boiling treatment using 3°Be sodium hydroxide liquor at 110 °C is now rarely encountered as it is a slow and expensive process [169]. [Pg.104]

Galbis et al. described a variety of carbohydrate-based linear polyesters 61 of the poly(alkylene dicarboxylate) type that were obtained by polycondensation reactions of the alditols 2,3,4-tri-(9-methyl-L-arabinitol (9) and 2,3,4-tri-O-methyl-xylitol (10), and the aldaric acids 2,3,4-tri-(9-methyl-L-arabinaric acid (26) and 2,3,4-tri-(9-methyl-xylaric acid (27), butanediol, and adipic acid were also used as comonomers [28]. Copolyesters of the poly(aIkylene-c )-arylene dicarboxylate) type were obtained using bisphenols as comonomers (Scheme 1). Chemical polycondensation reactions were conducted in bulk or in solution. Enzymatic polycondensation reactions of adipic acid with the above-mentioned alditols were carried out successfully using Lipozyme and Novozyme 435. The hydrolytic degradations of some of these polyesters were also described. [Pg.154]

A common feature of vapor-phase thermohydrolysis, liquid-phase acid hydrolysis, and enzymatic hydrolysis of cellulose is a significant influence of lateral order on the rate of chain cleavage, the DP finally reached, and weight loss. But with regard to this influence of the physical structure of cellulose, there also exist remarkable differences between these three modes of hydrolytic degradation. [Pg.144]


See other pages where Enzymatic and hydrolytic degradation is mentioned: [Pg.243]    [Pg.26]    [Pg.303]    [Pg.945]    [Pg.105]    [Pg.39]    [Pg.61]    [Pg.254]    [Pg.237]    [Pg.94]    [Pg.94]    [Pg.442]    [Pg.253]    [Pg.269]    [Pg.324]    [Pg.155]    [Pg.243]    [Pg.26]    [Pg.303]    [Pg.945]    [Pg.105]    [Pg.39]    [Pg.61]    [Pg.254]    [Pg.237]    [Pg.94]    [Pg.94]    [Pg.442]    [Pg.253]    [Pg.269]    [Pg.324]    [Pg.155]    [Pg.296]    [Pg.9]    [Pg.21]    [Pg.391]    [Pg.257]    [Pg.90]    [Pg.90]    [Pg.109]    [Pg.391]    [Pg.304]    [Pg.215]    [Pg.518]    [Pg.167]    [Pg.83]    [Pg.76]    [Pg.234]    [Pg.23]    [Pg.471]    [Pg.56]    [Pg.133]    [Pg.139]    [Pg.140]    [Pg.362]    [Pg.86]   


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Enzymatic degradability

Hydrolytic

Hydrolytic and Enzymatic Degradation of PLA

Hydrolytic degradation

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