SYNOPSISThe triethylenetetramine (TETTA) surface-modification process for fibers, consisting of short-time annealing and high-temperature treating the fibers previously padded in TETTA, has been developed. The annealing (60 s, 1'70°C) of the fibers was performed to restrict the reaction on the surface. To characterize the structure and properties of TETTA-modified fibers, IR spectroscopy, DSC, and X-ray diffraction were applied and critical dissolution time, dye uptake, density, and basic physical-mechanical properties were determined. It was shown that after annealing and aminolysis of the fibers Tg increases to 115"C, while the crystallinity index (determined by DSC) is changed from 33 to 46% (X-ray crystallinity increased from 47 to 59%) and critical dissolution time increased from 12.9 to 58.9 min, depending on the time of aminolysis. The results obtained suggested the existence of two simultaneous processes during the aminolysis: macromolecular scission responsible for introducing the amine groups at the surface and partial crystallization of PET. INTRODUCTIONThe properties of composites are often tailored by fiber hybridization. Thus, the impact resistance of C fiber-reinforced epoxy matrix composites can be increased by incorporating organic fibers, such as P E T and PE, into the composite structure, without noticeably damaging the other basic mechanical properties of the composite material (CM).' However, the interface fiber/matrix adhesion in hybrid composites is still among the key factors influencing the overall composite properties. Therefore, being extremely inert, PE, PET, and other organic fibers used as reinforcements in the CM usually undergo different surface modification prior use.Among the methods of modification, fiber-surface activity, low-temperature plasma treatment, as well as chemical modification with low molecular weight compounds are often applied to increase the compatibility toward and adhesion to common polymer matrices.' In our previous work,3 surface-aminated PET fibers were used in C fiberlepoxy resin com-* To whom correspondence should be addressed.Journal of Applied Polymer Science, Vol. 62, 605-612 (1996) TETTA was shown to be quite efficient, it seems too difficult to be accepted for industrial scale. T o simplify the surface-modification process, a twostage procedure was developed, consisting of shorttime annealing and then high-temperature treating of the fiber with TETTA, as described in detail elsewhere.5 I t was previously established t h a t under the proposed conditions the reaction with T E T T A occurs exclusively in the thin surface layer of the fiber via a macromolecular scission mechanism.This present article deals with the basic parameters of t h e structure and properties of aminated PET fibers. EXPERIMENTAL MaterialsThe polyester fabric cloth used was in the form of filament woven fabric cloth made from filament yarns of dtex 140, 48 filaments, and 150 twist. Threads per cm for the fabric were 25 in ends and 24 in picks. All chemicals were of reagent gra...

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Abstract:The influence of different temperature of drying after mercerizing on enzymatic scouring through changes in the surface properties and scouring efficiency were investigated. Mercerized cotton yarns dried at room temperature (20 o C) and 80 o C were scoured with alkaline and acid pectinases. Alkaline scouring was also done for comparing. Surface properties and scouring efficiency were followed through the CIE whiteness degree, CIELAB coordinates, X-ray photoelectron spectroscopy, staining the non-cellulosic components with appropriate dyes, wettability and surface fee energy. Mercerization changes the cotton surface, and removes part of the cuticle components. Drying at 80 o C melted down the residual waxes covering the surface of the fiber, enhancing the alkaline and alkaline pectinase scouring and enabling acid pectinase scouring. While way of scouring has significant influence on the most measured properties, temperature of drying has significant influence on CIE whiteness, CIELAB coordinates a*, b*, L* BB and on x-ray photoelectron spectroscopy value O/C.

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Melt nucleation and crystallization behavior of homo‐isotatic polypropylene (homo‐iPP), maleic anhydride (MAH)‐grafted‐iPP, and MAH‐modified iPP, produced from iPP and a small amount of MAH‐grafted‐iPP, was investigated by polarizing optical microscopy (POM), at Tc = 121–135oC. Nucleation processes at a given Tc were faster for modified PP as compared to neat iPP. The induction time for nucleation increased nonlinearly with increasing Tc and decreased for modified PP, probably as a result of promoted heterogeneous nucleation due to the presence of carbonyl groups of MAH‐grafted‐PP. The average spherulite sizes were decreased by modification, and the growth rate was enhanced in maleated PP and modified PP. The induction time approach was applied to the results obtained by POM to compare the tendency for heterogeneous nucleation of neat and MAH‐modified PP. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3107–3118, 2000