The in situ polymerization of vinyl monomers in polyester yarns

The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 120°C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and γ-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller γ-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers.     

The effects of selected organic solvents on the polymerization of acrylic acid to poly(ethylene terephthalate) by glow discharge

Six organic solvents with solubility parameters close to those of poly(ethylene terephthalate) (PET), namely, dimethyl sulfoxide, γ-butyrolactone, dimethyl formamide, pyridine, tetrachlorethane, and chlorobezene, were selected as swelling agents to promote the incorporation and the subsequent polymerization of acrylic acid to PET films. Variables studied included time of swelling, temperature of swelling, and length of glow discharge treatment. Elevated temperature had greater effects on the inclusion of the swelling agents and acrylic acid than did the length of swelling. Polymerization was generally increased with longer glow discharge treatment time. Surface wettability as well as the moisture regain values of PET films were greatly improved by both the solvent and the glow discharge treatments. The solvent-assisted glow discharge polymerization process was found to impose modification of PET films not restricted to the surface. Morphological modification of the treated PET was confirmed by DSC data.     

Vinyl graft polymerization-induced modification of some properties of poly(ethylene terephthalate) fabric

Polymerization of glycidyl methacrylate (GMA), methyl methacrylate (MMA), and acrylic acid (AA)/styrene (St) mixtures with poly(ethylene terephthalate) (PET) fabric to different polymer add-ons was performed. Moisture regain, dyeability, and soiling properties of the modified PET were examined. It was found that introduction of poly(GMA) in PET structure brings about (a) improved moisture regain, (b) enhanced dyeing with disperse dyes, (c) affinity and possible dyeing with acid, direct, and reactive dyes, (d) improved aqueous and nonaqueous oily soil resistance, and (e) decreased ease of soil removal. The magnitude of moisture regain, dyeability, and soiling properties are dependent upon the percent of polymer add-on. Polymerization of MMA with PET improved the dyeability of the latter with the disperse dye as well as its resistance to nonaqueous oily soil while decreasing the resistance to aqueous soiling and ease of both aqueous and nonaqueous soil removal. In the case of PET polymerized with poly(AA/St), there was a considerable enhancement in moisture regain, dyeing with the disperse dye, and resistance to aqueous and non-aqueous oily soiling. On the other hand, both aqueous and nonaqueous soil characteristics of PET were imparted by polymerization of the latter with AA/St mixtures.     

Graft copolymerization of styrene,methylmethacrylate, and acrylonitrile onto jute fibres

The contribution of jute constituents, namely, water soluble matters, waxes, pectins, lignin, hemicelluloses, and α-cellulose in the graft copolymerization reaction of jute fabric with some vinyl monomers was investigated. Styrene, methylmethacrylate, and acrylonitrile were used as the monomers and Fe²⁺/H₂O₂ redox system as initiator. The graft copolymerization reaction was carried out at 80°C using different concentrations of monomer and initiator for different lengths of time. The water soluble matters, pectins, and lignin were found to accelerate the graft copolymerization reaction during the initial stages of the reaction and in the meantime impede termination during the latter stages of the reaction. Generally, the magnitude of grafting is governed by nature of the substrate, nature of the monomer, and the conditions of the polymerization reaction. Grafting decreases the moisture regain of jute and substrates derived thereof irrespective of the monomer used within the range studied. Also, grafting decreases the tensile strength and imparts rot-proofing properties to the substrates examined.     

Improvement of hydrophilicity of polypropylene by liquid-phase mutual irradiation of acrylics

N-butanol was found to promote the inclusion of methyl acrylate and methyl methacrylate in polypropylene, but did not affect the uptake of acrylic acid in the polymer. Polymerization of the monomers was, however, not significantly affected by the use of this swelling agent. The monomer exchange process followed by a liquid phase mutual irradiation has proved to be very effective in enhancing the polymerization of all three monomers on polypropylene. Optimum radiation doses for effective polymerization of the monomers were found to be around 3.2 Mrad for methyl acrylate and around 4.8 Mrad for methyl methacrylate and acrylic acid. Surface wettability of the film and moisture regain of the fiber were tremendously improved with all monomers regardless of the swelling agent and temperatures. Also, a low radiation dose of 1.6 Mrad was as effective as the higher doses. Methyl acrylate and methyl methacrylate modified fibers showed no marked changes in strength and elongation, but did result in a harsher hand. Acrylic acid modified fibers increased greatly in elongation, decreased to a greater extent in strength, and softened in hand.     

Modification of polyester fabric properties by surfactant‐aided surface polymerization

Poly(methyl methacrylate) (PMMA) was applied to polyester fabric using a surface analog of emulsion polymerization. The admicellar polymerization was carried out using 1.5 mM dodecylbenzenesulfonic acid (DBSA) at pH 4 with 0.15M NaCl, 1 : 8 DBSA:monomer, and 1 : 10 initiator:monomer molar ratio. The PMMA film, which was formed, was characterized by SEM and FTIR. Hydrolysis of the PMMA film on polyester fabric was carried out to introduce carboxylic acid groups to the polyester surface to increase its hydrophilicity. The results show that a PMMA thin film was successfully formed on the polyester fabric. The water contact angle of the PMMA‐coated polyester fabric after hydrolysis by 10M H₂SO₄ for 5 h was reduced from 117.3° to 0° and there was a significant increase in the moisture‐regain value of the treated fabric. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4059–4064, 2007     

接枝改性腈纶织物亲水性能的研究

利用等离子体辐照引发聚丙烯腈纤维大分子,进行反相微乳液接枝聚合,在腈纶织物上接枝季胺盐类单体(F单体),以改善腈纶织物的亲水性能,借助红外光谱和扫描电镜对改性腈纶进行表征,探讨了改性腈纶织物的吸水性、回潮率、透气性及力学性能与其接枝率的关系。结果表明:F单体已接枝到腈纶织物上,接枝率和回潮率呈线性关系;当接枝率为20%左右时,回潮率达到约7%;当接枝率小于20%时,对腈纶织物透气性影响较小;随着接枝率的增加,腈纶织物的抗弯刚度减小,断裂强力和伸长有所增加。     

Enhancing oil repellency of electron beam-grafted polyethylene terephthalate fabric with 2-(perfluorohexyl) ethyl acrylate monomer via pre-irradiation

Electron beam (EB)-induced graft polymerization is advantageous for the surface modification of fabrics. We investigated the effect of monomer concentration and the addition of alkyl groups on the oil repellency of polyethylene terephthalate (PET) fabrics treated with monomers containing fluoroalkyl groups through EB-induced graft polymerization via pre-irradiation. We use 2-(perfluorohexyl) ethyl acrylate (FEA) and stearyl acrylate (SA(C18)) with long alkyl chains as vinyl monomers to induce reaction with radicals generated from EB irradiation. The weight gain and surface morphology of the PET fabrics change with the FEA monomer concentration. The uniformity of the EB-grafted PET fabric surface is determined at low monomer solution concentrations. Results of X-ray photoelectron spectroscopy analysis show that adding 0.1 mol/L of FEA monomer to the EB-grafted PET fabric yields the highest dodecane contact angle of 93.4° and a surface fluorine concentration of 39.8%. The addition of SA(C18) monomer to the FEA monomer decreases the dodecane contact angle by 77.5° and yields a surface fluorine concentration of 19.1%. EB graft polymerization via pre-irradiation results in a uniformly treated surface, and stable oil repellency is achieved when using solely the FEA monomer at a lower monomer concentration than that used in a similar irradiation method reportedly previously.     

塑料膜复合用水性丙烯酸胶黏剂的研究

采用乳液聚合法制备了一种水性丙烯酸胶黏剂,可用于塑料膜的复合。研究了功能单体、乳化剂、引发剂对胶黏剂性能的影响。结果发现,软/硬单体比例为60/40~65/35,功能单体AA与HEA占丙烯酸单体用量的5%,乳化剂占丙烯酸单体用量的1%～2%,引发剂占丙烯酸单体用量的0.6%,得到的乳液胶黏剂性能最佳,其剥离强度最高可达1.8N/15mm。     

Surface modification of poly (ethylene terephthalate) fabric by soy protein isolate hydrogel for wound dressing application

In this study, a composite of poly (ethylene terephthalate) (PET) fabric and soy protein isolate (SPI) hydrogel loaded with gabapentin was developed. For covalent attachment of SPI on the surface of PET fabric, graft polymerization of acrylic acid (AA) on the surface of PET fabric was performed and then carboxyl groups available in the structure of AA were activated using EDAC and then SPI was coated on the surface of PET fabric. The results revealed appropriate connection between hydrogel and modified fabric. The hydrogel was characterized by swelling test and the drug release behavior was investigated. It was found that the casting temperature affects the swelling ratio of the hydrogel and an appropriate release profile of the drug was observed. The surface of fabric was characterized by contact angle measurement, electron microscopy, and infrared spectroscopy. In vitro cell culture study was performed using NIH 3T3 mouse fibroblasts to investigate the biocompatibility of final composite and MTS results along with morphology of cells on the surface of PET fabric coated with SPI revealed the biocompatibility of final product and no cell cytotoxicity was observed in modified PET fabric.     

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     

有机硅改性聚丙烯酸酯粘合剂的合成及性能表征

以过硫酸钾(KPS)为引发剂、苯乙烯(ST)为硬单体、丙烯酸异辛酯(EHA)和丙烯酸丁酯(BA)为软单体、丙烯酸(AA)为功能单体,端乙烯基硅油为有机硅改性剂,制备了有机硅改性聚丙烯酸酯乳液;并将其作为粘合剂配成印花色浆,应用于棉织物的涂料印花中。研究了端乙烯基硅油用量对乳液聚合反应、乳胶膜性能及印花色浆的印花性能的影响,并对有机硅改性聚丙烯酸酯乳液进行了红外光谱及电镜表征。结果表明,端乙烯基硅油用量为单体总质量的6.5%时,乳液外观、胶膜性能及印花性能都较好。     

The effect of N,N-dimethylformamide and polymer grafting on the morphology of polyester fibers in fabric substrate

Photo-induced graft polymerization of acrylic acid (AA) and methyl acrylate (MA) in the liquid and vapor phase, respectively, onto N,N-dimethyformamide (DMF)-pretreated poly(ethylene terephthalate) (PET) fibers in fabric substrate was studied. The effect of various synthesis conditions and DMF pretreatment on the graft yields on PET was investigated. The internal morphology and properties of DMF-pretreated and grafted PET fibers in the fabric were characterized using density and birefringence measurements, differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR), dyeing methods, and critical dissolution times. The grafting was promoted by increasing DMF pretreatment temperature and the amount of DMF retention in the PET. Increasing biacetyl and monomer flow time and irradiation time enhanced grafting. DMF pretreatment resulted in increases in total void content, degree of crystallinity, trans-isomer content, chain folding, segmental mobility, and molecular packing of the PET, but caused decreases in its amorphous orientation, intermolecular forces, and individual void size through longitudinal shrinkage, lateral swelling, and removal of oligomers. Subsequent graft copolymerization led to further changes in the internal morphology and properties of the PET. PET grafted with AA had a higher cohesive energy density, lower degree of molecular packing, and larger individual void size, but less total void content, lower segmental mobility, less chain orientation, and a lower degree of crystallinity. PET grafted with MA showed increases in total void content, individual void size, segmental mobility, and molecular packing, but showed decreases in chain orientation and degree of crystallinity. © 1996 John Wiley & Sons, Inc.     

Surface modification of poly(ethylene terephthalate) fibers via controlled radical graft polymerization

Functional chemical modifications on poly(ethylene terephthalate) (PET) fibers via radical graft polymerization could be controlled by managing mutual interactions and affinities between different components in the grafting reaction system. Hansen solubility parameters was used as a tool to quantify affinities of related agents and the polymer, and provided reliable results. The latest results proved the practicality of using Hansen solubility parameters in controlling radical graft polymerizations on surface modifications of PET fibers. Four different monomers with different hydrophilic properties in different solvent and initiator systems were examined, and results confirmed that interactions of initiator‐PET, initiator‐solvent, monomer‐PET, monomer‐solvent, and monomer‐initiator play important roles in determining the grafting reaction efficiency. Results revealed that for the selected grafting systems studied, hydrophilic monomers presented overall favoring affinities toward PET leading to higher grafting yields compared to hydrophobic monomers. The results have instructive impact to commercial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45990.     

Surface graft polymerization of ionic monomers onto poly(ethylene terephthalate) by UV-irradiation without degassing

Graft polymerization of anionic and cationic monomers was performed onto the surface of poly(ethylene terephthalate) (PET) film with a simultaneous UV irradiation method, but using no photo-sensitizer. To effect graft polymerization, the PET film was immersed in an aqueous solution containing a monomer and periodate (NaIO₄) of appropriate concentrations, followed by UV irradiation without degassing. The monomers used were 2-acrylamide-2-methylpropane sulfonic acid and acrylic acid as anionic and N,N-dimethyl aminopropyl acrylamide and dimethyl aminoethyl methacrylate as cationic monomer. The role of NaIO₄ at the polymerization was to make the concentration of oxygen dissolved in solution zero by the photochemical reaction with the oxygen. The surface structure of grafted films was characterized by their contact angle, dyeing, X-ray photoelectron spectroscopy, and zeta potentials. Graft polymerization took place, not merely on the outermost surface, but also within the thin surface region of the PET film without any change in bulk properties. © 1993 John Wiley & Sons, Inc.     

涤纶辐射接枝改性的研究

本文用~(60)Coγ射线研究了丙烯酸在涤纶织物上的辐射接枝共聚反应。探讨了单体浓度、辐照剂量及阻聚剂等对接枝率的影响,并且测试了所得接枝物的吸湿性、染色性和物理机械性能。随着接枝程度的提高,吸湿性和染色性有明显的提高,但机械性能有所下降。     

棉织物无甲醛防皱整理剂MA-IA-AA共聚物的合成及性能

国内首次以马来酸(MA)、衣康酸(IA)和丙烯酸(AA)为单体,采用水相聚合工艺制备了MA/IA/AA共聚物,目标产物得到红外光谱检测证实。产物用作无甲醛纺织品防皱整理剂,研究了聚合条件对共聚物溴值和抗皱整理效果的影响。结果表明,在n(MA)∶n(IA)∶n(AA)=1∶1∶1、温度85℃、引发剂滴加时间为2 5h、m(引发剂)/m(总单体)=0 09时,制备的聚合多元羧酸的溴值低于43mg/g,单体转化率达到94%,聚合物相对分子质量为871。用该聚合物整理后,棉织物折皱回复角(WRA)可达到286°,提高率为83 3%,与公认效果最好的丁烷四羧酸(BTCA)整理后棉织物折皱回复角289°几乎一样。整理后的棉织物经水洗50次后,WRA仍可保持在263°,比水洗前的286°仅仅下降8%。整理后棉织物白度为77 6%。     

Moisture regain and dyeability of poly(acrylic acid)- and poly(styrene)-carbamoylethylated cotton graft copolymers induced by gamma radiation

Gamma radiation-induced graft copolymerization of either acrylic acid or styrene onto untreated cotton, alkali-treated cotton, and carbamoylethylated cottons having 0.392% N, 0.524% N, 0.725% N, 1.379% and 1.546% N was investigated under different conditions. Moisture regain and dyeability of these substrates before and after copolymerization were also examined. It was found that the graft yield increases by increasing monomer concentration and radiation dose irrespective of the monomer or substrate used. Using water-ethanol mixtures as polymerization media are advantageous for grafting of styrene. With both monomers, however, the graft yield for the modified cottons are substantially higher than untreated and alkali-treated cottons, indicating that the presence of carbamoylethyl in the molecular structure of cotton cellulose affords additional sites for graft copolymerization. Copolymers obtained using acrylic acid show much higher moisture regain that the ungrafted substrates, particularly when the carboxylic groups of the graft were in the sodium form. The opposite holds true for copolymers brought about by grafting with styrene. The color strength of all substrates dyed with a direct or a reactive dye decreases significantly after copolymerization with poly(acrylic acid) prior to dyeing. On the other hand, this copolymerization improves the affinity of the substrates for the basic dye and brings about perceptible shade. Copolymerization of the substrates in question with poly(styrene) improves the color strength of these substrates when dyed with direct, disperse, and basic dyes but decreases the color strength upon dyeing with a reactive dye.     

聚丙烯酸酯压敏胶的研制及在反光膜中的应用

以丙烯酸异辛酯(EHA)和丙烯酸丁酯(BA)为软单体,甲基丙烯酸甲酯(MMA)为硬单体,丙烯酸(AA)和丙烯酸羟丙酯(HPA)为交联单体,过氧化苯甲酰(BPO)为引发剂,乙酸乙酯为溶剂,采用溶液聚合法制备了一种溶剂型聚丙烯酸酯压敏胶。考查了各单体用量对压敏胶综合性能的影响。结果表明,当软单体质量分数为85%、MMA质量分数为5%、AA质量分数为6%和HPA质量分数为4%时,PSA综合性能优异,可满足反光膜的使用要求。     

水性苯乙烯-丙烯酸-马来酸酐共聚物的合成及表征

以过氧化苯甲酰为引发剂、二丙二醇二甲醚为溶剂,采用自由基聚合方法,合成苯乙烯-丙烯酸-马来酸酐三元共聚物。考察单体配比、引发剂用量、反应温度对聚合物性能的影响,并用红外光谱、凝胶色谱、差示扫描量热法等对共聚物进行表征。结果表明,最佳工艺条件是:n(ST):n(AA):n(MA)=6:3:1,反应温度为85℃,引发剂为单体质量的12%;得到数均分子量为4678、分子量多分散指数为1.45的三元共聚物。