聚丙烯无纺布预辐射接枝改性及胺化研究

采用丙烯酸(AA)、二乙烯三胺(DETA)依次对聚丙烯(PP)无纺布进行预辐射接枝改性及胺化处理,研究了接枝反应及胺化反应的影响因素,并用红外光谱对产物进行表征。结果表明:随着AA用量的增加,接枝率呈先增长后下降趋势;随着反应温度的升高,反应时间的延长,接枝率增加;随着接枝率的增大,胺化反应温度的升高及反应时间的增加,胺化率增加。接枝反应温度为95℃,25 mL AA与无纺布反应2 h,接枝率可达到276%;接枝率为250%的无纺布与50 mL DETA反应7 h,胺化温度205℃,胺化率可达到73%。红外光谱分析表明,经辐射接枝及胺化处理后的PP无纺布有胺基基团。     

Graft polymerization of acrylic acid onto macroporous polyacrylamide gel (cryogel) initiated by potassium diperiodatocuprate

Potassium diperiodatocuprate-initiated graft polymerization was found to be an efficient and convenient method for grafting of acrylic acid (AAc) onto superporous polyacrylamide gels, so called cryogels (pAAm cryogels). It was possible to achieve grafting degrees as high as 70% with about 25% yield of grafted polymer with respect to the initial amount of monomer. The superporous structure of the cryogels promoted grafting by providing an ample surface of the gel for grafting, ensuring good mass transfer inside the gel sample and allowing to wash easily both homopolymer of AAc and insoluble by-products formed during the polymerization reaction. The grafted cryogels could be dried at 60 °C and re-swollen with retaining their properties. The adsorption of water vapours by dried pAAm cryogels was marginally dependent on the degree of grafting. The swelling of AAc-grafted pAAm cryogel increased pronouncedly with increasing pH. The adsorption of low-molecular weight ligand, Cu(II), by AAc-grafted pAAm cryogels increased linearly with the degree of grafting, while binding of high-molecular weight ligand, lysozyme, increased linearly till the degree of grafting of about 40% followed by a sharp, nearly three-fold increase in lysozyme binding when the degree of grafting increased from 60 to 70%. The results indicate that a ‘tentacle’-type binding of lysozyme to grafted polyAAc takes place after a certain degree of grafting has been reached.     

Surface modification of synthetic fiber nonwoven fabrics with poly(acrylic acid) chains prepared by corona discharge induced grafting

The surface modification of synthetic fiber fabrics via corona discharge treatment and subsequent graft polymerization was investigated. Polyethylene (PE) nonwoven fabric and polyamide-6 (PA-6) nonwoven fabric were used as base fabrics. Acrylic acid (AAc) was graft polymerized onto the fabrics via corona discharge pre-treatment. The grafted amounts of PAAc were dependent on the grafting time, that of PA-6 being higher than that of PE. It was confirmed that the surface of the fibers constructing the fabric was fully covered with PAAc after the 20 min reaction. The surface of the PAAc grafted fabrics was characterized by X-ray photoelectron spectroscopy. The leakage of electrostatic charge from the fabric was determined and the dyeability was studied with methylene blue. The period of time in which the charge potential attenuated to 1/2 of the initial potential decreased drastically by grafting with PAAc. The grafted amount was enough for dyeing the entire fabrics.     

Preparation of chelating fabrics by radiation‐induced grafting of itaconic acid and acrylonitrile onto polypropylene nonwoven fabrics and subsequent amination of graft copolymer

A mixture of acrylonitrile (AN) and itaconic acid (IA) was cografted onto polypropylene (PP) nonwoven fabrics by preirradiation method. The effects of graft polymerization conditions such as temperature, reaction time, Mohr's salt concentration, solvent mixture ratio, and comonomer composition on the total grafting yield were investigated. The addition of AN as a comonomer increased the amount of IA that reacted with PP fabrics. An increase in the temperature from 40 to 60°C increased the grafting rate, but the final grafting yield decreased at high temperature. The addition of 0.01 wt % Mohr's salt to the reaction medium leaded to a sharp increase of grafting yield. The accelerative effect of solvent medium on the grating yield was higher in dimethylformamide (DMF) and methanol mixtures, when compared with DMF or methanol. Chelating fabrics was synthesized by subsequent amination of grafted fabric with ethylene diamine (EDA) and phenylhydrazine (PH). The conversion yield reached maximum value at about 90% for 80% PP‐g‐AN‐IA fabrics at 90°C. At same amination conditions, the conversion yield is higher when PP‐g‐AN‐IA fabrics react with EDA compared with PH. FT‐IR data indicate that amine groups were introduced onto PP‐g‐AN‐IA fabric through amide linkage between grafted AN or IA and EDA or PH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Functional finishing by using atmospheric pressure plasma: Grafting of PET nonwoven fabric

Poly (ethylene terephtalate) (PET) nonwoven fabric was treated with He/O₂ plasma to produce peroxides and grafted with acrylic acid (AA) for introducing carboxyl groups onto PET surface. The graft yield increased with AA concentration from 1.5M to 2.5M, and then decreased with further increase in AA concentration. Graft yield increased with sodium pyrosulfite (SPS) concentration from 0.005M to 0.02M, and then decreased with further increase of SPS concentration. X‐ray photoelectron spectroscopy results indicated that both of plasma treatment and AA grafting increased oxygen content and decreased carbon content on the PET nonwoven fabric surface. The grafted PET nonwoven fabric showed increase in moisture regain and dye uptake. And drastic increase in wettability was observed after grafting. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3655–3659, 2007     

Effect of matrix graft modification using acrylic acid on the PP/Mg(OH)2 composites and its possible mechanism

The matrix graft modification using an acrylic acid (AAc) was employed on the polypropylene/Mg(OH)₂ flame-retardant composite. The graft modification of PP matrix was carried out via an in-situ reactive extrusion by a twin-screw extruder. The tensile strength of the composites was analyzed using an equation developed by Pukanszky from which both matrix tensile strength σ₀ and interfacial adhesion strength were found to be increased. The enhancement of σ₀ is due to the intermolecular crosslinking of PP by AAc grafting. This crosslinking causes increases of tensile strength, Young’s modulus, impact resistance, and thermal resistance, but decreases the elongation at break of the composites.     

Study of modified polypropylene nonwoven cloth. I. graft copolymerization of 4‐vinylpyridine onto polypropylene nonwoven cloth by preirradiation method

Polypropylene (PP) nonwoven cloth was grafted with 4‐vinylpyridine (4‐VP) by a preirradiation method. The effects of preirradiation conditions on the mechanical properties of preirradiated PP nonwoven cloth and the percentage of grafting (Pg) of 4‐VP onto the preirradiated PP nonwoven cloth were systematically investigated. The results indicated that the mechanical properties of preirradiated PP nonwoven cloth decreased with increasing irradiation dose and that the Pg was greatly affected by the concentration of monomer, irradiation dose, grafting reaction temperature, and the addition of inhibitor and inorganic acid in the grafting reaction system. The grafted nonwoven cloth samples were characterized using IR spectroscopy and SEM. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1861–1868, 2000     

聚乙烯纺粘非织造布生产技术初探

采取高温纺丝和较低的侧吹风速度冷却,在聚丙烯(PP)纺粘生产线上生产聚乙烯(PE)纺粘非织造布,探讨了其生产工艺。结果表明:采用熔融指数(每10min)20g的PE为原料,选择纺丝温度250℃,侧吹风速度1.5～1.8m/s,侧吹风温度16～18℃,气流速度5000m/min,生产的PE纺粘非织造布单丝线密度2.16dtex,断裂强度0.68～1.61cN/dtex,断裂伸长率150%～165%。     

阻燃PP纺粘无纺布的性能研究

研究了阻燃母粒法和整理法制得的阻燃PP纺粘无纺布的力学性能、热性能和阻燃性能。结果表明:阻燃母粒法制得的阻燃PP纺粘无纺布的断裂强力与PP纺粘无纺布的接近,但断裂伸长率要低,后整理法制得的纺粘无纺布的力学性能与PP纺粘无纺布的接近;两种方法制得的阻燃PP纺粘无纺布的热性能均优于PP纺粘无纺布,在1000℃左右时,有24.0%～33.2%的炭残渣,成炭性较好;两种方法制得的阻燃PP纺粘无纺布的阻燃性能良好,其中用阻燃剂B整理后的PP纺粘无纺布其阻燃效果优于阻燃剂A整理的PP纺粘无纺布。     

Preparation of acrylic acid grafted polypropylene nonwoven fabric by photoinduced graft polymerization with preabsorption of monomer solution

We improved photoinduced graft polymerization by absorbing the monomer solution onto the substrate (Ab‐type) instead of immersing the substrate in the monomer solution (Im‐type) before photoirradiation to yield a more practical and effective grafting system. With this system, acrylic acid (AA) was effectively grafted onto polypropylene (PP) nonwoven fabric. The maximum degree of grafting obtainable was restricted by the amount of monomer preabsorbed onto the PP fabric. However, we effectively enhanced the degree of grafting by increasing the monomer concentration, adding trimethylolpropane triacrylate (TMPTA) to the monomer solution, and repeating the photoirradiation with supplementation of the monomer solution. The net availability of the monomer for graft polymerization was 50% or greater; this increased to 90% or greater with the addition of TMPTA and was much higher than for conventional Im‐type photografting (≤13%). Fourier transform infrared spectra, scanning electron microscopy morphology observations, and the adsorption–regeneration properties confirmed that the PP‐g‐AA fabric prepared by the improved Ab‐type photografting method had comparable qualities to those of fabric prepared by conventional Im‐type photografting. Thus, the improved Ab‐type photografting system provides potential for the preparation of graft adsorbents on a large scale at a competitive cost with a continuous reactor, such as a conveyer belt system, instead of a batch reactor. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Properties of grafted polymer metal complexes as ion exchangers and its electrical conductivity

A polyelectrolyte has been prepared, as a potential proton exchange polymer, by grafting acrylic acid/acrylamide (AAc/AAm) and acrylic acid/acrylonitrile (AAc/AN) comonomers onto a low‐density polyethylene film via gamma irradiation. The developed polymers were characterized by evaluating their physico‐chemical properties such as ion exchange capacity (IEC) and electrical conductivity as functions of grafting yield. The grafted film at different compositions was characterized by Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. IEC of the grafted film at grafting % 191 and monomer concentration ratio 50:50 for (LDPE‐g‐AAc/AAm) was found to be more than that for (LDPE‐g‐AAc/AN). The electrical conductivity was found to be greatly affected by the comonomer composition, were it increased as the degree of grafting increased for all grafted films. After alkaline treatment with 3% KOH (3% potassium hydroxide), the electrical conductivity of the grafted films found to be increased. The presence of potassium as counter ion maximized the electrical conductivity of the grafted films. The electrical conductivity of Cu‐membrane complexes was higher than that of both Co (cobalt) and Ni (Nickel) complexes. It has been indicated that, the electrical conductivity increased by increasing both Cu ion content and temperature. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers.     

Antibacterial activities of acrylic acid-grafted polypropylene fabric and its metallic salt

Acrylic acid (AAc) was grafted onto polypropylene (PP) fabric by a preirradiation method using a ⁶⁰Co gamma ray. The effects of the absorbed dose, the reaction temperature, reaction time, storage time, as well as the addition effect of ferrous ion and sulphuric acid on the degree of grafting, were determined. It was shown that the synergistic effect of a strong acid with ferrous sulfate can increase the grafting yield. Antibacterial activities on metallic complexes of acrylic acid-grafted polypropylene (AAc-g-PP) fabric were evaluated by a viable cell counting method. An Ag complexed fabric had strong biocidal effect for all bacteria. Fe, Cu, and Zn complexed fabrics had different antibacterial activities depending on each bacterium. However, AAc-g-PP fabric and Ni-complexed fabric did not have bactericidal effect. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2213–2220, 1998     

Gamma preirradiation and grafting of 2N-morpholino ethyl methacrylate onto polypropylene fabric

The radiation-induced grafting of 2N-morpholino ethyl methacrylate (MEMA) in aqueous solution onto polypropylene fabric by a preirradiation technique has been investigated. Among the most important factors affecting the graft yield are monomer concentration, irradiation dose, reaction temperature, and time. It was found that the graft yield increased with increasing monomer concentration, grafting temperature, and preirradiation dose. The kinetic studies showed that the dependence of the grafting rate on monomer concentration is of 1.1 order. Moreover, the calculated overall activation energy was 14.2 kcal/mol. The grafted PP fabric shows an increase in moisture regain with increasing graft yield. Also, the dyeability with acid dye was significantly increased due to grafting with MEMA. © 1995 John Wiley & Sons, Inc.     

Anti‐bacterial and swelling properties of acrylic acid grafted and collagen/chitosan immobilized polypropylene non‐woven fabrics

The various weight ratios of collagen/chitosan were used to immobilize the various grafted amounts of acrylic acid (AA) grafted polypropylene nonwoven fabric. For a given value of grafting percentage of AA and the immobilizing time period, the values of the immobilizing percentage of collagen/chitosan are increased with the increasing of chitosan contained in the mixtures of collagen/chitosan. The antibacterial properties are also increased with the increasing of chitosan in the mixtures of collagen/chitosan and the immobilizing percentage of collagen/chitosan. The crosslinking reaction between the AA‐grafted PP nonwoven fabrics and collagen/chitosan with glutaraldehyde are clearly sustained by examination from the spectra of the surface reflection infrared spectroscopy (IR). The values of water uptake and water diffusion coefficients are decreased with the increasing of chitosan in the mixtures of collagen/chitosan and the immobilizing percentages of collagen/chitosan at the same pH value of buffering water. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 391–400, 2005     

Graft Copolymers of Polypropylene Films. 1. Radiation-induced Grafting of Mixed Monomers

Radiation graft copolymerization of comonomer mixtures of acrylic acid (AAc) and styrene (S) onto polypropylene (PP) films by the mutual method has been investigated. The effect of different factors that may affect the grafting yield, such as inhibitor concentration (Mohr’s salt), solvent composition (MeOH and H₂O), radiation dose and dose rate, was studied. It was found that Mohr’s salt was very effective when the content of AAc in the comonomer mixtures was low. However, the addition of 1·25wt% of Mohr’s salt reduced homopolymer formation and enhanced the grafting process. Graft copolymerization in the presence of a solvent mixture composed of methanol and water was found to afford a higher grafting yield than in pure methanol, regardless of the composition of the comonomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H₂O: 80% MeOH and a comonomer mixture of 20% AAc: 80% S. An attempt was made to determine each PAAc and PS fraction by different methods in the graft copolymer obtained. Elemental analysis indicated that the PAAc fraction with respect to PS in the graft copolymer decreased with increasing AAc ratio in the comonomer feed solution. The rough assessment of these fractions by IR spectroscopy showed similar trends. The reactivity ratios of AAc and S monomers determined in the present graft copolymerization system were found to be 0·45 and 1·3, respectively. © of SCI.     

Fabrication of deodorizing fabric by grafting of metal phthalocyanine derivative onto nonwoven polypropylene fabric

Fabrication of deodorizing fabric was tried by grafting metal phthalocyanine derivative, a catalytic deodorant, onto polypropylene (PP) nonwoven fabric. Fe(III)-4,4′,4″,4‴-tetra carboxamide phthalocyanine (Fe-TCMP) was synthesized. The Fe-TCMP showed high-deodorizing performance when tested for the elimination of 2-mercaptoethanol, an index material for bad-smelling compounds. The Fe-TCMP was converted to Fe(III)-4,4′,4″,4‴-tetracarboxylic acid phthalocyanine (Fe-TCAP) by hydrolysis to have carboxyl groups. It was chemically grafted on the surface of PP nonwoven fabric, which was surface modified to have amine groups with diaminocyclohexane (DACH) plasma. Such fabricated deodorizing fabric showed high-deodorizing performance for 2-mercaptoethanol. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 839–846, 2001     

Ammonia adsorption behavior of polypropylene nonwoven fabric grafted with acrylic acid

An attempt was made to synthesize an adsorbent by the photoinduced grafting of acrylic acid (AA) onto polypropylene nonwoven fabrics using benzophenone (BP) as a photosensitizer in a CH₃OH/H₂O medium. As the BP concentration was increased, the graft yield was increased up to a specific value and then decreased, and the effect of AA concentration showed the same tendency. It was also found that the graft yield increased with the reaction time and temperature. The amounts of ammonia adsorbed onto polypropylene nonwoven fabrics grafted with AA (PP‐g‐AA) were dependent on the graft yield, adsorption time, and ammonia gas pressure. The adsorption capacity of PP‐g‐AA was 5.86 mmol/g at the graft yield of 116.6%, which was much higher than that of active carbon or silica gel. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 295–301, 2002; DOI 10.1002/app.10328     

丙纶在非织造布工业中的应用现状及前景

介绍了丙纶的特性、丙纶在非织造布工业上的应用情况及应用领域和发展趋势。指出了一次性用丙纶非织造布具有十分广阔的市场前景,预计在21 世纪丙纶非织造布将继续高速增长     

Radiation grafting of hydrophilic monomers onto poly(4-methylpentene-1), II. Grafting of long chain monomers and physical properties of the grafted films

Radiation grafting of 2-hydroxyethyl methacrylate (HEMA) and methoxytetraethyleneglycol methacrylate (M4G) on low crystallinity poly(4-methylpentene-1) (TPX) has been investigated. Grafting yield increased with increasing pre-irradiation dose, grafting temperature, and monomer concentration. Grafting rate depends on length of molecular chain in the monomers and decreases with increasing chain length. The grafting yields of electron beam irradiated samples were higher than those of γ-irradiated ones because of higher radical concentration. Tensile strength of the grafted film in the dried state increased and the elongation at break decreased with increasing degree of grafting. On the other hand, in the wet state, the tensile strength and elongation at break decreased with increasing the degree of grafting due to the lack of hydrogen bonds between the grafted chains caused by increased water absorption.     

Free radical grafting of glycidyl methacrylate onto polypropylene in a co-rotating twin screw extruder

Free radical grafting of glycidyl methacrylate (GMA) onto molten polypropylene (PP) was studied in a co-rotating twin screw extruder. Grafting yields of GMA obtained under various experimental conditions along the screw length allowed for a good appreciation of the effects of chemical parameters (the presence of styrene and the concentrations of peroxide and monomers) and those of processing parameters (feed rate, screw speed, and specific throughput). Similar to the results obtained in a batch mixer,¹ free radical grafting of GMA carried out in the extruder in the presence or absence of styrene proceeded rapidly, as it was virtually completed half-way down stream of the extruder. Additionally, the presence of styrene as a second monomer increased the GMA grafting yield reatly with reduced PP chain degradation. The ultimate GMA grafting yield increased with increasing concentration of peroxide, 1,3-bis(tert-butylperoxyisopropyl)benzene. This similarity between the batch mixer and the extruder is related to the fact that in both cases it is the concentration of the peroxide and its half lifetime that determine the grafting rate and the ultimate grafting yield. On the othe hand, the GMA grafting yield decreased with increasing screw speed or feed rate. For a particular specific throughput (the ratio of throughput to screw speed), an increase in throughput with a concomitant increase in screw speed brought about a decrease in GMA grafting yield. It was concluded that the GMA grafting yield is affected primarily by the residence time in the zone in which free radicals are not depleted. The effects of screw speed, feed rate, and specific throughput manifest mainly through this local residence time distribution. Specific energy is not a good measure of the performance of the extruder with respect to the free radical rafting of GMA onto PP. © 1995 John Wiley & Sons, Inc.