Development and characterization of poly(trimethylene terephthalate)‐based bicomponent meltblown nonwovens

Poly(trimethylene terephthalate) (PTT)‐based mono and bico meltblown webs have been produced by using a Reicofil® Bi‐Component Meltblown Line at TANDEC, located at the University of Tennessee, Knoxville, TN. Thermal and flow properties of PTT were first examined by DSC (differential scanning calorimetry) and with a Melt Indexer for an effective experimental design through the Surface Response Methodology (SRM). The processability of meltblowing in a wide range of operating windows was extensively investigated. Melt temperature, melt throughput, air temperature, airflow rate, and DCD (distance of collector to die) were considered as primary process control variables. The produced webs were characterized for fiber diameter, bulk density, air permeability, hydrostatic head, tensile properties, and heat shrinkage. Non‐round and curly or twisted fibers were observed in the bico PP/PTT webs by SEM (scanning electrical microscope). The PTT grade studied is quite suitable for the meltblown process. The PTT/PP‐based bico webs showed enhanced barrier properties and heat resistance. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1280–1287, 2002     

Study of polypropylene/poly(ethylene terephthalate) bicomponent melt‐blowing process: The fiber temperature and elongational viscosity profiles of the spinline

Although there are significant differences between high‐speed melt spinning and melt blowing (MB), they are similar in many important components. This study, motivated by the need to better understand the bicomponent MB process, used the basic theories of high‐speed melt spinning to estimate the fiber temperature and elongation viscosity profiles of the polypropylene/poly(ethylene terephthalate) (PP/PET) bicomponent MB process. During the MB process, the filament temperature decreased dramatically within the first 2 in. from the MB die. The fiber temperature‐decay profiles of PP, PET monocomponent, and PP/PET bicomponent filaments followed similar trends. PP filaments attenuated faster than PET filaments and the bicomponent filaments attenuated at a medium rate between that of PP and PET. Accordingly, the elongational viscosity increased significantly in the first 2 in. from the die. PET filaments exhibited higher elongational viscosity than that of 100% PP filaments. The elongational viscosity profile of 75%PP/25%PET was between that of PP and PET monocomponent filaments. These data provided important information on understanding the MB process and filament attenuation. It also suggested that the filament elongational viscosity profile is the key factor in production of finer bicomponent MB fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1145–1150, 2003     

Properties of PP/PET bicomponent melt blown microfiber nonwovens after heat‐treatment

Polypropylene (PP)/poly(ethylene terephthalate) (PET) bicomponent (bico) fibres are successfully melt blown in the Reicofil® meltblown (MB) pilot line commissioned at the Textiles and Nonwovens Development Center (TANDEC), the University of Tennessee, Knoxville. The bico fibers possess a cross‐sectional side‐by‐side configuration. The originally expected greater fiber crimp due to density and fine structure gradients on the different sides of the bico fibers was not commonly observed in the normal MB webs. These fabrics were exposed to dry heat for a period of time. The properties before and after the heat treatment were determined and compared to investigate the effects of heat on their properties. It was found that the bico webs are thermal dimensionally stable and many of their properties were not significantly affected. A mechanism is suggested on the thermal dimensional stability of the PP/PET bico MB webs. © 2003 Society of Chemical Industry     

PET/PTT复合纤维卷缩性能的研究

通过对不同线密度的聚对苯二甲酸乙二醇酯/聚对苯二甲酸丙二醇酯(PET/PTT)复合纤维的热收缩率、卷曲收缩率、卷曲模量及卷曲稳定度的测试,研究了干热和沸水处理条件下的PET/PTT复合纤维的卷缩性能。结果表明:干热处理时,PET/PTT复合纤维的热收缩率随温度的升高而升高,随线密度的提高而减小;与干热处理比较,沸水加压处理后的纤维具有较好的热收缩率和卷曲性能。PET/PTT复合纤维线密度越低,其卷曲收缩能力越强,线密度为172 dtex时,纤维表现出较好的卷曲收缩率和卷曲稳定性。     

Preliminary study on fiber splitting of bicomponent meltblown fibers

Side‐by‐side bicomponent meltblown fiber webs were developed on REICOFIL® bicomponent (bico) meltblown line at The University of Tennessee's Textiles and Nonwovens Development Center (TANDEC), using polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), polytrimethylene terephthalate (PTT), and so forth. The posttreatment was performed by hydroentanglement to investigate the fiber‐splitting behavior in this research. Microscopy analysis and SEM were applied to examine the web structure. The change in web property after posttreatment and the adhesion mechanism of the polymer interface were also addressed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2090–2094, 2004     

An investigation of fiber splitting of bicomponent meltblown/microfiber nonwovens by water treatment

Meltblowing is a most versatile and cost‐effective process commercially available worldwide to produce microfiber nonwovens directly from thermoplastic resins. The new bicomponent (bico) meltblown technology opens a great possibility to make even finer microfibers by subsequently fiber splitting. Water‐dispersive Eastman AQ polymers were initially introduced to the meltblown process to make the mono‐ and bicomponent meltblown webs at Textiles and Nonwovens Development Center (TANDEC), University of Tennessee, Knoxville. The postwater treatment was performed on the fabrics, which resulted in the dispersive part (AQ polymer) being dispersed in water and only the other part remaining in the bico web. A process–structure–property study is provided toward the research reported in this article. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1218–1226, 2004     

Thermal oxidative degradation of bicomponent PP/PET fiber during thermal bonding process

The effects of the thermal bonding temperature, dwell time, and the type of mold materials on the thermal oxidative degradation of the PP sheath of bicomponent fibers were investigated using the Fourier Transform Infrared Spectra (FTIR) and Thermal Gravimetry/Differential Scanning Calorimetry (TG‐DSC) techniques. The samples were prepared on a new 3D nonwovens process based on air‐laying and through‐air thermal bonding. The fiber material was a commercial polypropylene (PP)/polyester (PET) (sheath/core) bicomponent staple fiber. The results reveal that ketone developed following β‐scission in the thermally bonded nonwovens. The level of thermal oxidative degradation increases with increase in the bonding temperature, dwell time, and the thermal conductivity of the mold material. Such thermal oxidative degradation led to the slight widening of the melting peaks of the fiber PP sheath in the thermally bonded nonwovens, and a slight decreasing of melting point compared with those of the as‐received fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 391–397, 2007     

Nanoparticle effects on structure and properties of polypropylene meltblown webs

The effect of nanoclay additive on the structure, morphology, and mechanical properties of polypropylene meltblown webs is reported here for the first time. Effect of nanoclay on the meltblown processing, resultant fiber web structure, and properties are discussed. Combination of wide‐angle x‐ray diffraction, differential scanning calorimetry, and transmission electron microscopy were used to determine the nature of clay dispersion in the polypropylene fiber matrix and resultant morphology. Transmission electron microscopy micrographs revealed nanolevel dispersion of the additive in the fiber web. Clay additive did not offer any benefit as far as the mechanical properties of the meltblown web are concerned. Meltblown web samples with nanoclay had higher variability in web structure, high air permeability, high stiffness, and lower mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

PP/PET混合型熔喷保暖材料的研制

研制了一种PP/PET混合型熔喷保暖材料,采用电子扫描显微镜分析了该熔喷材料的纤网形态结构,并对其透气性、保暖性以及力学性能等进行了测试。结果表明：加入PET纤维之后,材料的纤网空隙增大,其透气性能得到提高;当PET纤维的质量分数为50%时,材料的保温率高达62.47%,强度为6.5 N/5 cm,是一种优良的保暖材料。     

Development and performance study of polypropylene/polyester bicomponent melt‐blowns for filtration

In this study, a new type of polypropylene (PP)/polyester (PET) bicomponent melt‐blown (bi‐MB) for filtration was developed through the melt‐blowing process with raw materials of melt‐blown (MB)‐grade PP and PET chips. The structure, porosity, and filtration performance of the bi‐MBs were tested through relevant instruments. The results show that the average fiber diameter in the bi‐MBs was 2–3.5 μm, the average pore size was 12.3–15.6 μm, and the porosity was 90–94%. The results also show that the filtration efficiency of the bi‐MBs was much higher than that of monocomponent PP MBs. It reached the highest value of 97.34% when the PP/PET ratio was 50/50 and could be used as high‐performance filter media. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

关于PS/PP系共混物的研究——第1报 PS/PP共混体系的相容性和相态结构

本研究以苯乙烯—乙烯—丁烯—苯乙烯嵌段共聚物(SEBS)和苯乙烯—乙烯—丙烯嵌段共聚物(SEP)为界面活性剂(相溶化剂),研究聚苯乙烯等规聚丙烯(PS/PP)共混体系的相容性;研究PS/PP两成分体系和添加界面活性剂后三成分体系的相态结构及相界面形态。为制取结构稳定的PS/PP系共混物,进一步制取具有特殊性能约PS/PP共混纤维提供实用的工艺条件和理论依据。     

锦丙皮芯复合纤维的研究

本文研究了锦丙皮芯复合纤维的加工工艺,解决了两种聚合物热性能和粘度差异及锦丙皮芯破裂给纺丝带来的技术难题。对纺丝、拉伸、热定型工艺取得了一系列数据,同时又分析了纤维的结构特性,所得结果对制取锦丙皮芯复合纤维具有理论指导意义。     

Effects of material and treatment parameters on noise‐control performance of compressed three‐layered multifiber needle‐punched nonwovens

The effects of material and treatment parameters on airflow resistivity and normal‐incidence sound absorption coefficient (NAC) of compressed three‐layer nonwoven composites have been studied. Material parameters included fiber size and porosity, and treatment factors included applied pressure and duration of compression. Fibers used included poly(lactic acid) (PLA), polypropylene (PP), glassfiber, and hemp. Three‐layered nonwoven composites were classified based on material content and fiber blend. LHL and PGP were sandwiched structures consisting of PLA/Hemp/PLA and PP/glassfiber/PP layers, respectively. PGI consisted of three layers of an intimate blend of PP and glassfiber. Statistical models were developed to predict air flow resistivity from material parameters and the change in air flow resistivity from compression parameters. Independent variables in the first model were porosity and fiber size and, in the latter model, were compressibility, pressure, and initial material parameters. An increase in air flow resistivity was found with increased compression. No significant effect of compression duration was detected. Two additional statistical models were developed for the prediction of sound absorption coefficient based on material and treatment parameters. The independent variables of the first model were air flow resistivity, thickness, and frequency, and those of the second model were compressibility, initial thickness, and initial density of the composite, diameter and density of the fiber, compression pressure, and frequency. A decrease in sound absorption coefficient was detected with increasing compression, while no effect of duration was detected. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical and thermal properties of bamboo fiber reinforced polypropylene/polylactic acid composites for 3D printing

In this article, a kind of degradable composite was prepared from bamboo fiber (BF), poly lactic acid (PLA), and polypropylene (PP). The mechanical and thermal properties were characterized by the universal testing machine, thermogravimetric analysis, differential scanning calorimetry. In order to improve the compability between BF and polymer matrix several modification on the surface of BF were explored and compared. Moreover, a compatibilizer (maleated PP) was applied to further increase compatibility between the fiber and matrix. It is found that the thermal stability of BF/PP/PLA composites decreased with the increase of maleated polypropylene (MAPP) content. When 5% MAPP was used the tensile strength, flexural strength, and impact strength of composites reached 33.73, 47.18 MPa, and 3.15 KJ/m², with an increase by 13, 11.7, and 23.5%, respectively, compared with the composites without MAPP. The improvement of mechanical properties is attributed to the fact that irregular grooves and cracks induced by the modification of BF facilitate the infiltration of polymer into fiber due to the strong capillary effect. Furthermore, BF/PP/PLA composites are potential to be used in 3D printing. POLYM. ENG. SCI., 59:E247–E260, 2019. © 2018 Society of Plastics Engineers     

Effect of lignin on mechanical,biodegradability, morphology,and thermal properties of polypropylene/polylactic acid/lignin biocomposite

ABSTRACT

The effects of lignin on mechanical, biodegradability, morphology, and thermal properties of PP/PLA/lignin were investigated. PP/PLA/lignin film were manufactured by adding PP, PLA, lignin and compatibilizer into rheomix at 200°C, at 70?rev?min^?1 for 30?minthen pressed using Hydraulic Hot Press at 200°C–210°C, at 6 bar for 20?min. The functional groups of PP/PLA/lignin were analyzed using FTIR. The surface morphology, mechanical properties and thermal stability was measured by SEM, tensile strenght and TGA respectively. TThe FTIR intensity of vibration peak of –CH₃?cm^-1 from PP/lignin and PP/PLA/lignin at 997–993, 1458–1451 and 2966–2904?cm^-1 was lower than neat PP. The addition of lignin into PP/lignin, PLA/lignin and PP/PLA/lignin can reduce tensile strength and elongation at break. The thermal stability PP/PLA/lignin was lower than the PP/lignin but higher compared to PP/PLA biocomposites. The biodegradability of PP/PLA/lignin biocomposites was two times higher than that of PP/lignin.     

热收缩性聚丙烯纤维的研究

研究了适于纺制高收缩聚丙烯纤维的树脂的性能特点。添加改性组分共混纺丝可以进一步提高所得纤维的热收缩性。对热收缩聚丙烯纤维的聚集态结构特点和热收缩过程中的结构变化进行了研究。结果表明 :结晶速率小的聚丙烯树脂所得纤维的热收缩率高 ,添加适当的改性剂共混纺丝得到了收缩率近 30 %的聚丙烯纤维 ;具有潜在热收缩性的聚丙烯纤维聚集态结构具有结晶度低、晶粒尺寸小、非晶区取向程度高的特点 ,热收缩过程是结晶度变大、晶粒尺寸变大、结构趋于完善的过程。     

Viscoelastic,thermo-mechanical and environmental properties of composites based on polypropylene/poly(lactic acid) blend and copper modified nanoclay

Poly(lactic acid) (PLA)/polypropylene (PP) blends composites were prepared by incorporating 3 wt.% of copper modified montmorillonite (MMT-Cu²⁺), obtained using cation exchange in a CuSO₄ solution, and 10 wt.% of polypropylene-graft-maleic anhydride (PP-g-MA) as a compatibilizer then varying the PLA content until 50 wt.%. These materials were subjected to several investigations such as X-rays diffraction, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and tensile and environmental tests. The DMTA analysis showed that the glassy PLA high stiffness and the PP crystalline phase compensate the decrease in the storage modulus occurring during the PP and PLA glass transitions, respectively. The variations of tan δ revealed no changes on the PP and PLA phases glass transitions temperatures which indicate the immiscibility of the two polymers, as supported by DSC analysis. Blends composites SEM micrographs stated the immiscibility of the system resulting in the poor adhesion of the PLA droplets to the PP matrix. Also, the blends composites exhibited intermediate tensile properties between those of PP and PLA. The incorporation of MMT-Cu²⁺ to the (50/50) PP/PLA blend accentuated its aptitude to water absorption and ensured an efficient antimicrobial activity over a satisfactorily long period of around six months.     

Effect of ammonium polyphosphate and acrylic acid on NaCl treated electrospun PLA microfiber mat

In this study, insulation material was developed using polylactic acid (PLA), which is one of the most widely-used biodegradable polymers. The PLA was fabricated into a fiber mat shape using the electrospinning method, and NaCl salt was added to achieve thinner fiber diameter. This fiber-based mat showed lower thermal conductivity than PLA blocks but had poor tensile strength and heat stability. To improve these mechanical and thermal properties, ammonium polyphosphate (APP) and acrylic acid (AA) were added; AA was used to better bond the APP with the polymer matrix. The APP/AA mixed PLA fiber mat showed improved performance overall; with the addition of these materials, the thermal conductivity was about 35 mW/mK, which was slightly lower than before, the tensile stress improved about two times. Thermal stability was also augmented as the increase in the weight percentage of the sample residue after the thermogravimetric analysis indicated.     

Natural-based polymers for antibacterial treatment of absorbent materials

In this study, polypropylene (PP) nonwoven fabric which can be used as topsheet layer of an absorbent hygienic product was modified by natural based antibacterial agents. Antibacterial herbal agents (cinnamaldehyde, geraniol, phenylethyl alcohol) were sprayed by ethanol or applied by means of polylactic acid (PLA) and polycyclohexene oxide (PCHO) based polymers prepared by three different chemical methods. Characterization of synthesized materials was conducted via thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy–energy dispersive X–ray spectroscopy (SEM-EDX). Besides characterization, antibacterial and pH buffering performances of antibacterial polymers alone and on PP fabric were tested by antibacterial and pH tests. Effects of antibacterial treatments on air permeability and absorption period of nonwoven fabrics were also analyzed. According to the results, biopolymers changed the thermal stability of PP nonwoven fabric. Antibacterial performances can be ranked as cinnamaldehyde, geraniol, and phenylethyl alcohol from the best. Besides a slight decrease about liquid absorption performance, all of the treated topsheet fabrics are sufficient for an absorbent hygienic product. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48302.     

聚丙烯微孔隔膜孔隙率与室温电导率关系探讨

采用国产具有不同孔隙率的聚丙烯微孔隔膜,探讨了其微观结构、收缩率、抗穿刺能力、电解液吸附能力与室温电导率之间的关系。结果表明:孔隙率太小,透气性能差,电解液吸附能力弱,电导率低;孔隙率为50%时,虽然透气性能和电解液吸附能力明显改善,但对应的收缩率和抗穿刺能力变差,电导率反而变低,因此,对于常用的聚丙烯微孔隔膜而言,孔隙率在45%左右比较合适。