Anton Marcinčin

Nucleation of the β-modification of isotactic polypropylene

The effects of the organic pigments C.I.P. RED 177 and C.I.P. Yellow 83 as nucleating agents on the crystallization of polypropylene were studied by DSC. The anthraquinone pigment exerted a significant effect, resulting in structural modifications with lower melting point, and particularly the β-modification. The DSC curves exhibit four transition regions, with the following temperature intervals: I. 415–417 K, II. 423–425 K, III. 430–432 K and IV. 438–439 K. For evaluation of the β-nucleation effect of pigments, the ratio (ΔH1+ΔH2)/(ΔH3+ΔH4) was suggested.

DSC Study of Syndiotactic Polypropylene/Organoclay Nanocomposite Fibers: Crystallization and Melting Behavior

The effect of anisotropic particles of organophilic layered silicate on the crystallization and melting behavior of prepared nanocomposite systems was studied. The matrix was syndiotactic polypropylene (sPP). Organophilic layered silicate M-QDA filler was prepared by modification of hectorite SOMASIF ME 100 with octadecyl amine. The compatibilizer was isotactic polypropylene (iPP) grafted with maleic anhydride (iPP-g-MA). The silicate was exfoliated in situ within the sPP during the melting process to produce anisotropic nanoparticles. The sPP/M-ODA nanocomposite was spun at different drawing ratios. The resulting fibers were examined by differential scanning calorimetry. It was found that neither the spinning process nor the presence of nanofiller affected the crystallinity of the sPP matrix of the nanocomposite in comparison with the neat sPP. At a raised drawing ratio of the fibers slightly increased crystallinity of matrix was observed; however, it was still lower than the neat sPP fibers prepared at the same drawing ratio. The presence of M/ODA nanofiller in sPP matrix increased the melting temperature of the fibers.

The DSC Study of PA 6, Polyamides and Copolyamides

The DSC method was used to obtain more information on changes of thermal properties connected with different comonomers bound in the (co)polymer chains. The copolyamides propered were block ones which were less crystalline and compatible with poly-ε-caprolactam. The results have confirmed the crystalline nature of polyamides and copolyamides.

Influence of the Composition of Polypropylene/Organoclay Nanocomposite Fibers on their Tensile Strength

The statistical method “Experimental Design” was applied to optimization of weight composition of isotactic poly(propylene)/organoclay (iPP/org.clay) nanocomposite fibers from the standpoint of achieving the desired tensile strength at break as one of the significant mechanical properties. These properties were studied on fibers prepared from samples of iPP/org.clay nanocomposites of differing compositions. According to the statistical program, there were thirteen samples prepared containing the organoclay filler,NANOFIL, in the concentration range 0.5 to 4.9 wt%, and compatibilizer, an iPP grafted with maleic anhydride (iPP‐g‐MA) of concentration from 1 to 5 wt%. The samples were spun, and the obtained fibers underwent measurements of tensile strength at break, σ. Evaluation of the obtained data, led to the establishment of an optimal compatibilizer to filler ratio (Comp./Fill.) of 0.16 to 2.76, for which the tensile strength is higher than for unfilled iPP fibers.

Preparation, properties and application of modified fibers with piperazine rings

ABSTRACTWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW The paper is devoted to the preparation of copolyamidesfrom e-caprolactam with 6.1–24.5 wt% of the nylon saltof adipic acid and 1-(2-aminoethyl)piperazine. Molecularcharacteristics and thermal properties of the preparedcopolyamides have been studied.Fibers from copolyamides and blend fibers containingpolyamide 6 and copolyamides have been prepared andtheirpropertieshavebeenevaluated.Modifiedfibershavebetter electrical properties, higher sorption of watervapour, lower orientation factor and tensile strength andpractically the same elongation at break in comparisonwith non modified polyamide 6 fibers. Copyright 1999John Wiley & Sons, Ltd.KEYWORDS: copolyamide; e-caprolactam; adipic acid;1-(2-aminoethyl)piperazine; blended fibers

NUCLEATION AND CRYSTALLIZATION OF POLYPROPYLENE FILLED WITH BaSO4

The influence of high concentration of BaSO4 as nucleating agent on crystallization of fiber-forming polypropylene was studied by DSC. The work presents experimental and calculated values of melting and crystallization enthalpies of filled polypropylene and the influence on the formation of interface interactions between filler and polymers. These results show minimal interactions of components (BaSO4 and polypropylene) under experimental conditions.

Polypropylene/Poly (Trimethylene Terephthalate)–Blend Fibers

Polypropylene (PP)/polyester (PES)–blend fibers were prepared by extruder melt spinning. The polymer blend consisted of PP and a “master batch” (MB) based on polytrimethylene terephthalate (PTT) or polyethylene terephthalate (PET), binary PTT/PET or PP/PTT blends, and also on a ternary PP/(PTT/PET) blend. The phase structure of PP/PES–blend fibers was examined. PES microfibers showed separation from the PP matrix in blend fibers. The impact of MB composition and rheological characteristics on phase structure parameters indicate a significant contribution of the PTT in the binary MB on the length of dispersed PES microfibers in the PP matrix. However, the blends of PP and ternary MB (PP/PTT/PET) have a lower diameter and length of the PES microfibers. The presence of PTT/PET (PES) enhances the structural and mechanical properties of the blend PP/PES fibers. In addition, PTT increases the tensile strength of the PP/PES–blend fibers if a binary MB is used, while the fiber nonuniformity is reduced in the presence of a ternary MB.

Fiber-forming blends of polypropylene and branched polyethylene

Abstract In this paper, some results obtained at preparation of fibers from polypropylene and low-density polyethylene (LDPE) blends are presented. In the framework of this topic, the influence of the concentration of LDPE in PP on preparation conditions, rheological properties, mechanical and thermal properties, and structure of polymer blends and blended fibers was investigated. Experimental value of the melt viscosity shows the negative declination from the additive ones. PP and LDPE form an incompatible system. Prevailing content of PE component has a positive influence on flow properties of the melt. Technological compatibility of fiber-forming PP-LDPE blend is very good at 60—80% of “non-fiber-forming” LDPE. Very good processing was reached when the dispersed PP phase formed the microfibrils in polyethylene matrix. In this case, the polyfibrillar structure of blended fibers was formed.

Spinning, mechanical and thermal properties of metallocene polypropylene fibers

The higher mechanical properties of polypropylene (PP) fibers based on metallocene-catalyzed PP (miPP) in comparison with fibers based on Ziegler–Natta-catalyzed PP (zniPP) were presented in periodic literature in the last decade. At the same time the miPP fibers have lower crystallinity and lower melting temperature compared with conventional zniPP fibers. In our experimental work, the thermal and mechanical properties of both the miPP and zniPP multifilaments depending on their spinning and drawing conditions were investigated. The dynamic viscosity and deviation from the Newtonian flow of polymer melt were evaluated as important parameters for melt-spinning technology. The melting temperature, melting enthalpy and melting entropy of multifilaments were investigated using DSC analysis in dependence on spinning temperature and draw ratio of fibers. At the same time the mechanical properties of fibers tenacity, elongation and elastic modulus were measured. The DSC measurements were carried out using conventional method and constant length method at which the constant length of fibers was held (constrained fibers). The changes in melting temperature, melting enthalpy and melting entropy of drawn fibers were analyzed and correlated with mechanical properties of fibers. The mechanical and thermal properties of fibers were discussed with regard to the spinning and drawing conditions as well.

Blended Polypropylene Fibers

The preparation, and especially the dyeability of blended fibers polypropylene and terpolymer acrylonitrile-butadiene-styrene and/or polypropylene and polystyrene, respectively are presented in this paper. Modified polypropylene fibers fix the dyestuffs much better and have lower tenacity according to the amount of the additive.