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Use of chitosan in surface modification of textile materials
No full textTextiles have long undergone surface modification to improve their softness, dyeability, absorbance, and wettability. Recent advances in textile chemistry have also approached textile surface modification to impart antimicrobial activity, decreased skin irritation, and even enhancing fragrance. Chitosan is an effective natural antimicrobial agent derived from Chitin, a major component in crustacean shells. Chitosan applied to textiles has been widely studied for effects such as shrink resistance, improved dye uptake, and as auxiliary or anti-static agents, etc., because of the low toxicity and good biocompatibility of this natural polymer. Coatings of Chitosan on conventional fibres appear to be the more realistic prospect since, they do not provoke an immunological response. In this article, I summarize some of the most recent development in surface modification of textile using chitosa
Polydimethylsiloxane modified chitosan. Part IV: Preparation and characterization of porous hybrid membranes
No full textINVESTIGATION ON FLAME RETARDANCY AND ANTIDRIPPING OF NOVEL INTUMESCETN FLAME RETARDANT TOWARDS A TRADITIONAL ONE ON POLYPROPYLENE
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Effects of sterically hindered N-alkoxyamines on photo-oxidative stability of reinforced polypropylene
No full textThe influence of sterically hindered N-alkoxyamine (such as Flamestab®NOR116) on the photo-oxidative stability of calcium carbonate reinforced polypropylene (CCPP) used for production of plastic collars has been investigated. The samples, prepared by melt compounding, were exposed to artificial accelerated photo-ageing carried out at »>300 nm and 45 oC in air. The aged samples were investigated by FT-IR and UV-visible spectroscopies. The results showed that the presence of Flamestab®NOR116 into CCPP induced a remarkable change of the kinetic of photo-oxidation such as a significant increase of oxidation induction time and reduction of oxidation rat
Functionalized Chitosan and Its Use in Pharmaceutical, Biomedical, and Biotechnological Research
No full textFormation and oxygen diffusion barrier properties of fish gelatin/natural sodium montmorillonite clay self-assembled multilayers onto the biopolyester surface
No full textIn order to expand the application of bio-derived polymers it is imperative that the issues related to their poor gas barrier properties be addressed. Here we explore the sequential layer by layer electrostatic selfassembly approach (abbrev. LbL) for modifying the oxygen transmission rate (OTR) of biopolyesters with the trademark - FF 1482® (abbrev. BP) by deposition of fish gelatin/natural montmorillonite clay (trademark - Cloisite Na+, abbrev. CloNa+). We will show that the deposition of fish gelatin/CloNa+ onto the BP surface is influenced by different process parameters such as dipping time, drying step, polyelectrolyte concentration and surface activation of the BP film via partial alkaline hydrolysis as well as via low pressure plasma. Micro-attenuated total reflectance Fourier-transform infrared spectroscopy (mATR-FTIR) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) showed that the traditional dipping LbL technique, which involves keeping the film wet throughout all deposition cycles, led to a heterogeneous multilayered structure. The addition of the drying step has proven to be a crucial parameter to obtain a quite homogenous fish gelatin/CloNa+ multi-layered structure. Further, the homogeneity of the multi-layered structure was considerable improved when both the CloNa+ concentration was increased and the BP film surface was activated. By exploiting these processing parameters we were able to achieve successful homogenous fish gelatin/CloNa+ multi-layered structures as shown by SEM/EDS analysis. Further, the optimised samples showed a drastic ecrease in OTR. For example, the OTR value for the sample, in which the BP surface was activated via plasma treatment prior to deposition of fish gelatin/CloNa+, was reduced by 97% of the corresponding value of untreated BP film. This remarkable barrier may be attributed to a greater dispersion of the impermeable inorganic CloNa+ platelets which forces the oxygen molecules to diffuse around them rather than take a straight line pathway that lies perpendicular to the film surface. Thus, this results is a long and tortuous pathway for oxygen molecule diffusion through the multilayered structure
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