Characterization of PET/PP blend fiber and it’s application to wig

As PET (Polyester) fiber has better heat resistance than PVC fiber or modacryl fiber, it has been used as wig fiber for human hair alternatives. However, PET is heavier and has higher specific gravity than human hair, and therefore the authors attempted to make lighter wig fiber by blending PP (polypropylene) into PET by mixing the PET/PP blend with a compatibilizer, a ethylene-acrylic ester-GMA(EAG) component grafted material, to overcome poor compatibilities of PET and PP. The thermal properties of the PET/PP blend mixed with EAG were measured using DSC, and the results showed that EAG affected melting point and crystallization temperature of the blend polymer. As blend ratio of PP increased, specific gravity of blend fiber reduced and thermal shrinkage rate increased. Blend ratio of PP was greater for shorter lengths of initial curl, although curl loosening increased as time elapsed.     

Thermal properties of Poly(trimethylene terephthalate)/Poly(ethylene terephthalate) melt blends

The thermal behavior, morphology, ester-interchange reaction of Poly(trimethylene terephthalate) (PTT)/Poly(ethylene terephthalate) (PET) melt blends were investigated over the whole composition range(xPTT/(1-x)PET) using a twinscrew Brabender. The melt blends were analyzed by differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (¹³C-NMR), and scanning electron microscopy (SEM). Single glass transition temperature (T _g ) and cold crystallization temperature (T _cc ) were observed in all melt blends. Melt blends were found to be due to the ester-interchange reaction in PTT/PET blend. Also the randomness of copolymer increases because transesterification between PTT and PET increases with increasing blending time. This reaction increases homogeneity of the blends and decreases the degree of crystallinity of the melt blends. In PTT-rich blends, mechanical properties decrease with increase of PET content compared with that of pure PTT. And, in PET-rich blends, tensile modulus decreases with increase of PTT content, but tensile strength and elongation is similar to that of pure PET.     

Effect of acrylonitrile content on the glass transition temperature and melt index of PVC/SAN blends

PVC and SAN are often mixed to compensate for the disadvantages of each polymer. Miscibility and thermal stability of PVC/SAN blend were investigated in this study by blending SAN polymer having 20, 24, 28, 32 % of acrylonitrile contents. Two polymers were mixed using a melt blending method with a single screw extruder. DSC them ogram was used to evaluate miscibility of the two polymers. SAN having 24 % of acrylonitrile showed the best miscibility with PVC. In order to evaluate degradation behavior, blended polymer was heat treated in DSC furnace and glass transition temperature was measured consecutively. Glass transition temperature increased continuously with annealing time due to degradation and cross-linking of polymer chains. Melt index of blended polymer was always higher than that of PVC.     

Synthesis and characterization of novel self-colored PET (polyethylene terephthalate) by step-growth polymerization containing dye based on 1,8-naphthalimide group

A novel self-colored polyethylene terephthalate (PET) was synthesized using a synthesized dye, 4-amino-N-propanoic acid-1,8-naphthalimide. For this purpose, the prepared naphthalimide dye was added upon the polycondensation step and then a self-colored PET was prepared by step-growth polymerization. The characterization of synthesized self-colored PET and naphthalimide dye were carried out using TLC, FTIR, ¹HNMR, DSC, UV-visible and Fluorometery. Results indicated that, the novel fluorescent yellow-green PET with appropriate properties was obtained. The glass transition temperature of self-colored PET was 70 °C and it was measured by differential scanning calorimeter, which revealed that addition of dye to the chains of polymer did not affect the context of glass transition of polymer. UV-visible spectrum indicated that, 99 percent of dye was incorporated in polymer chains chemically. Furthermore, the intrinsic viscosity of self-colored PET was 0.556 dl/g and molecular weight of polymer was around 35000 (g/mol) and measured using the viscometer technique.     

Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Processing and characterization of liquid crystalline copoly-(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate)/polycarbonate blends

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of PET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10∼30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40∼50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.     

The effects of blend composition and blending time on the ester interchange reaction and tensile properties of PLA/LPCL/HPCL blends

PLA/LPCL/HPCL blends composed of poly(lactic acid) (PLA), low molecular weight poly(ε-caprolactone) (LPCL), and high molecular weight poly(ε-caprolactone) (HPCL) were prepared by melt blending for bioabsorbable filament sutures. The effects of blend composition and blending time on the ester interchange reaction by alcoholysis in the PLA/LPCL/HPCL blends were studied. Their thermal properties and the miscibility due to the ester interchange reaction were investigated by¹H-NMR, DSC, X-ray, and UTM analyses. The hydroxyl group contents of LPCL in the blends decreased by the ester interchange reaction due to alcoholysis. Thus, the copolymer was formed by the ester interchange reaction at 220 °C for 30–60 minutes. The thermal properties of PLA/LPCL/HPCL blends such as melting temperature and heat of fusion decreased with increasing ester interchange reaction levels. However, the miscibility among the three polymers was improved greatly by ester interchange reaction. Tensile strength and modulus of PLA/LPCL/HPCL blend fibers increased with increasing HPCL content, while the elongation at break of the blend fibers increased with increasing LPCL content.     

Polyester fiber production using virgin and recycled PET

In this study, the design and construction of an extrusion equipment with spinning fiber devices has been developed to produce polyester fiber from virgin and recycled polyethylene terephthalate (PET). Several operating parameters (i.e., pressure, temperature, feed flow rate, extrusion speed and extruder design) have been analyzed to identify the best process conditions. In particular, this study has focused on a detailed analysis for the processing of recycled raw material for polyester textile fiber applications considering the variability of the process and identifying alternatives to minimize the impact on the quality parameters such as the fiber diameter and mechanical specifications. The experimental results were compared with the values calculated using a theoretical model, which has been developed for these particular cases. The mathematical analysis of the mass flow showed a very good agreement with respect to the experimental data, where there was a percentage difference < 3 %. It was found that the fiber diameter is a function of intrinsic viscosity (VI) or melt flow index (MFI). Finally, the mechanical properties of the fibers were evaluated and results indicated that the fiber with higher average molecular weight showed higher tenacity and lower Young’s modulus values.     

Simultaneous enhancement of impact toughness, mechanical properties and thermo-dimensional stability of epoxy composites by rubber-coated exfoliated graphite nanoplatelets

Exfoliated graphite nanoplatelets (EGN) were successfully coated with a liquid rubber amine-terminated poly(butadiene-co-acrylonitrile) (ATBN) at various concentrations. The rubber-coated EGN was incorporated into epoxy resin at different contents. The result revealed that the impact toughness of EGN/epoxy composite was increased by about 18 % with increasing the ATBN coating concentration. The impact strength, the flexural and dynamic mechanical properties, and the thermo-dimensional stability of EGN/epoxy composites were simultaneously enhanced by the incorporation of 1 wt% EGN coated with 10 wt% ATBN rubber into epoxy, which turns out a very small amount of 0.1 wt% ATBN compared to the epoxy resin.     

Fluorescence characterization of LaRC PETI-5, BMI, and LaRC PETI-5/BMI blends

In the present study, the fluorescence behavior of a phenylethynyl-terminated imide (LaRC PETI-5) resin, a bismaleimide (BMI) resin, and various LaRC PETI-5/BMI blends with different blend compositions has been characterized as a function of heat-treatment temperature, using a steady-state fluorescence technique with a front-face illumination method for solid-state films. It is observed that there are distinguishable changes in the spectral shape, size, and position of fluorescence with varying heat-treatment temperature in the pure and blend samples. The result is qualitatively explained in terms of charge transfer complex formation as well as microenvironmental change with local mobility and viscosity occurring in the LaRC PETI-5, BMI, and their blends during the cure process. The result also implies that a steady-state fluorescence technique may be a useful tool to understand the processing conditions of polyimides and their blends in the film form on the basis of their thermo-photophysical responses.     

Low temperature shape recovery effect of polyurethane copolymer grafted with pendant <Emphasis Type="Italic">n</Emphasis>-butyl group

Effect of the pendant n-butyl group on shape recovery and tensile properties of polyurethane (PU) block copolymer was investigated. The grafted n-butyl group was intended to keep PU chains away and to deter molecular interaction between PU chains by its flexible chains, and thus improve shape recovery at subzero temperature while maintaining high and reproducible tensile properties and shape recovery at ambient temperature. The attachment of n-butyl group did not make any change in the molecular interaction and phase separation of hard and soft segments in PU structure as judged from IR and DSC analysis. Cross-link density and intrinsic viscosity increased with the increase of n-butyl content due to the partial cross-linking by the linking reagent. Shape recovery and shape retention were not diminished after cyclic shape memory tests. Finally, the effect of n-butyl group on low temperature shape recovery was compared with linear ones and the potential application of this finding was discussed.     

Effects of date palm leaf fiber on the thermal and tensile properties of recycled ternary polyolefin blend composites

This work investigated the effects of date palm leaf fiber (DPLF) content on the thermal and tensile properties; and morphology of compatibilized polyolefin ternary blend. Recycled polyolefin ternary blend consisting of low density polyethylene (RLDPE), high density polyethylene (RHDPE) and polypropylene (RPP) were fabricated at different parts per hundred resin (phr) of DPLF. Maleic anhydride grafted polyethylene (MAPE) was used as compatibilizer to enhance the adhesion between filler and polymer matrix. The composites were prepared using melt extrusion and tests samples were produced via injection molding process. Thermal conductivity results showed that as much as 11 % reduction in thermal conductivity was achieved with the incorporation of 30 phr DPLF. Highest tensile strength was observed with the incorporation of 10 phr DPLF. The elongation at break was reduced with the addition of DPLF due to impediment of chain mobility by the fillers. Initial degradation temperature increased with the addition of DPLF. Hence, it is concluded that DPLF can be used to develop green and thermally insulating composites. It is hoped that the present results will stimulate further studies on the thermally insulative materials based on natural fibers reinforced polymer composites for applications in the building industries.     

Studies on the ternary blends of liquid crystalline polymer and polyesters

Thermotropic liquid crystalline polymer made up of poly(p-hydroxybenzoate) (PHB)-poly(ethylene terephthalate) (PET) 8/2 copolyester, poly(ethylene 2,6-naphthalate) (PEN) and PET were mechanically blended to pursue the liquid crystalline phase of ternary blends. Complex viscosities of blends decreased with increasing temperature and PHB content. DSC thermal analysis indicated that glass transition temperature (Tg) and melting temperature (Tm) of blends increased with increasing PHB content. Both tensile strength and initial modulus increased with raising PHB content and take-up speed of monofilaments. In the WAXS diagram, only PEN crystal reflection at 2Θ=15.5^o appeared but PET crystal reflection was not shown in all compositions. The degree of transesterification and randomness of blends increased with blending time but sequential length of both PEN and PET segment decreased.     

Flame retardancy,Thermal and mechanical properties of Kenaf fiber reinforced Unsaturated polyester/Phenolic composite

Unsaturated polyester (UP) resin has been blended with phenolic resin (PF) resole type at various ratios to obtain a homogeneous blend with improved flame resistance compared to its parent polymers. The polymer blend was reinforced with 20 wt% kenaf using hand lay out technique. Fourier transform infrared spectroscopy (FT-IR) was used to characterize changes in the chemical structure of the synthesized composites. The thermal properties of the composites were investigated using thermogravimetric analysis (TGA). The thermal stability of UP/PF kenaf composites co-varies with the PF content, as shown by the degradation temperature at 50 % weight loss. The char yield of the composites increases linearly with PF content as shown by the TGA results. The flammability properties of the composites were determined using the limiting oxygen index (LOI) and UL-94 fire tests. The LOI increased with the PF content while the composites exhibit improved flame retardancy as demonstrated by UL-94 test. The mechanical and morphological properties of the composites were determined by tensile test and scanning electron microscopy (SEM), respectively. The tensile strength and the Young’s modulus of the blend/composites slightly decreased with increasing PF content albeit higher than PF/kenaf fiber composites.     

Synthesis and hydrophilicities of Poly(ethylene 2,6-naphthalate)/Poly(ethylene glycol) copolymers

Poly(ethylene 2,6-naphthalate) (PEN)/Poly(ethylene glycol) (PEG) copolymers were synthesized by two step reaction during the melt copolymerization process. The first step was the esterification reaction of dimethyl-2,6-naphthalenedicarboxylate (2,6-NDC) and ethylene glycol (EG). The second step was the condensation polymerization of bishydroxyethylnaphthalate (BHEN) and PEG. The copolymers contained 10 mol% of PEG units with different molecular weights. Structures and thermal properties of the copolymers were studied by using¹H-NMR, DSC, TGA, etc. Especially, while the intrinsic viscosities of PEN/PEG copolymers increased with increasing molecular weights of PEG, but the glass transition temperature, the cold crystallization temperature, and the weight loss temperature of the copolymers decreased with increasing molecular weights of PEG. Consequently, the hydrophilicities by means of contact angle measurement and moisture content of the copolymer films were found to be significantly improved with increasing molecular weights of PEG.     

Use of maleated castor oil as biomodifier in unsaturated polyester resin/fly ash composites

Maleated castor oil (MACO) was prepared and was used as biomodifier in unsaturated polyester resin (UPE)/fly ash composites. The prepared MACO was characterized for its molecular weight and viscosity. MACO was blended with UPE in three different ratios like 5, 10 and 15 wt%. Fly ash was incorporated in the blend matrix (10 wt%) and curing was done by free radical polymerization. MACO was polymerized and crosslinked with UPE in situ during the formation of the composites. The cured matrix therefore formed an interpenetrating polymer network and the enhancement in properties was significant. Incorporation of 5 wt% MACO was most effective compared to 10 and 15 wt%, when the impact strength increased by 52% without any loss in modulus. The glass transition temperature also shifted to a higher temperature indicating strong intercomponent bonding in this set of composites.     

Various nano-silica particles affecting dyeability of poly(ethylene terephthalate)/silica nanocomposite films

Poly(ethylene terephthalate) [PET] based nanocomposites containing three differently modified silica particles were prepared by melt compounding. The influence of type of nano-silica on dispersibility, thermal and dyeing properties of the resultant nanocomposite was investigated by various analytic techniques, namely, polarized optical microscopy (POM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), reflectance spectroscopy (RS), and light fastness. Optical microscopy images illustrated that nano-silica particles tended to increase the number of spherulites in the PET matrix which were dependent on nano-silica type and content. Thermal studies of the resultant nanocomposites showed a slight decrease in the melting temperature compared to a pristine PET. Silica nanocomposites were finally dyed with a disperse dye and their reflectances were determined by the aid of reflectance spectrophotometer. Such reflectances were converted to the corresponding color coordinate values which are indicative of dyeability of such nanocomposites.     

Physical properties of cryomilled rice starch

Cryomilling of rice starch was evaluated as a non-chemical way to modify starch structure and properties. Cryomilling in a liquid nitrogen bath (63–77.2 K) was done to Quest (10.80% amylose) and Pelde (20.75% amylose) rice starch at five different time frames (0, 15, 30, 45, and 60 min). The viscosity of the cryomilled rice starch decreased significantly (p < 0.05) with increasing milling duration, including peak viscosity, hot-paste viscosity, cold-paste viscosity, breakdown, and consistency. Increasing milling time significantly increased (p < 0.05) water solubility index and water absorption index. Infra-red spectroscopy and X-ray diffraction crystallography both showed that the crystallinity of the cryomilled starch decreased with increasing milling time. Differential scanning calorimetry (DSC) analyses showed that after 60 min cryomilling there was partial loss of crystallinity (86% for Quest and 91% for Pelde) of both cryomilled starches. The cryomilling process modified the rice starch by causing a loss of crystallinity, that reduced its pasting temperature and increased water absorption, and by fragmentation of starch (probably the amylopectin fraction) that reduced the viscosity and increased solubility.     

Matrix modification with silane coupling agent for carbon fiber reinforced epoxy composites

To improve interfacial adhesion between carbon fiber and epoxy resin, the epoxy matrix is modified with N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (YDH602) and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (YDH792), respectively. And the effect of matrix modification on the mechanical performance of carbon/epoxy composites is investigated in terms of tensile, flexural and interlaminar properties. The flexural properties indicate that the optimum concentration of silane coupling agents YDH602 and YDH792 for the matrix modification is approximately 0.5 wt% of the epoxy resin system, and the mechanical properties of the YDH792-modified epoxy composites is better than that of the YDH602-modified epoxy composites at the same concentration. Compared to unmodified epoxy composite, the incorporation of 0.5 wt% YDH792 results in an increase of 4, 44 and 42 % in tensile, flexural and interlaminar shear strength (ILSS) values of the carbon/epoxy composite, respectively, while the corresponding enhancement of tensile and flexural modulus is 3 and 15 %. These improvements in mechanical properties can be considered to be an indication of better fiber/matrix interfacial adhesion as confirmed by SEM micrographs of the fracture surface after interlaminar shear testing. The viscosity of the modified epoxy resin system can be reduced by incorporation of silane coupling agent YDH792, which is beneficial for fiber impregnation or wetting during liquid composite molding process.     

Investigation on flame retardancy of poly(ethylene terephthalate) for plastics and textiles by combination of an organo-modified sepiolite and Zn phosphinate

Zn phosphinate, organo-modified sepiolite and poly(ethylene terephthalate) (PET) have been melt blended to develop a new flame retardant system for PET plastics and textiles. The combination of Zn phosphinate and sepiolite have been exploited in order to enhance the flame retardancy of PET for both plastics and textiles. The thermal stability of PET blends evaluated by thermogravimetric analysis and differential scanning calorimetry results remarkably affected by the loaded fillers. The combustion tests by cone calorimetry reveal a relevant decrease of combustion rate and a high increase of fire performance index for both plastics and textiles due to the presence of this novel flame retardant mixture. Analogously, limiting oxygen index has been found increased in a remarkable way.