Graft copolymerization of methyl methacrylate onto polypropylene oxidized with ozone

After the reaction of polypropylene by ozone oxidation, methyl methacrylate was graftcopolymerized onto the polypropylene. The active species determined by ESR spectroscopy as a peroxyl radical was converted to hydroperoxide, and the hydroperoxide was broken by heating, giving alkoxyl and hydroxyl radicals, the former of which initiated graft copolymerization. The effect of the ozone-oxidation time and polymerization time on the graft copolymerization was investigated. At the constant polymerization time, the total conversion and the degree of the grafting increased with the ozone-oxidation time, while the graft efficiency decreased. On the other hand, at the constant oxidation time, the total conversion and the degree of grafting increased with the polymerization time, while the graft efficiency decreased. These results were compared with a polyethylene case. The mechanism of the ozone oxidation and the initiation of the graft copolymerization were also discussed.     

Some features of heterophase graft polymerization on synthetic fibers from thermoplastic polymers

Conclusions A considerable effect of structural-physical properties and molecular dynamics of the polymer as a solid on the process of radical graft polymerization to fibres from thermoplastic polymers which have been spun from the melt has been found.In the case of heterophase graft polymerization of vinyl monomers to polypropylene fibre, it has been shown that orderedness of the polymer structure primarily affects the initiation stage.High kinetic parameters of heterophase graft polymerization in oriented systems from thermoplastic polymers can be realized only at temperatures which exceed the glass point of the polymer matrix.Moscow Textile Institute. Translated from Khimicheskie Volokna, No. 1, pp. 7–9, January–February, 1987.     

Mechanism of adhesion of low surface energy materials treated with trialkylborane

Excellent adhesion to low surface energy materials without surface pretreatment was obtained by acrylates polymerization initiated by trialkylborane at room temperature. The adhesion mechanism was elucidated by electron spin resonance (ESR) and gas chromatography-mass spectroscopy (GC-MS) analysis based on model compound and chain transferring agent technologies. On the other hand, polypropylene (as one kind of low energy surface materials) was treated with trialkylborane and its effects were also studied by attenuated total reflection Fourier transform infrared spectroscopy (FTIR-ATR) and Raman spectroscopy, static contact angle measurements. The result provided further supports the elucidated mechanism.The results showed the adhesion resulted from the monomer’s graft on the surface of low surface energy materials. The graft resulted from the hydrogen abstraction reaction of materials (not less than three hydrogen sites) by alkoxyl and other radicals. These radicals came from oxidation of trialkylborane through the cleavage of O−O bond of R₂BOOR. The adhesion was caused neither by the materials’ surface energy improvement nor by the copolymerization of polymerizable monomers and unsaturated groups on the surface of materials.     

Computer control of fibre manufacturing from graft copolymers of polycaproamide

Conclusions Possibilities of computer control over the amount of graft polymer and rate of the graft polymerization reaction have been investigated.A method has been proposed for determining the amount of grafted polymer and the rate of graft polymerization using a microcomputer.Translated from Khimicheskie Volokna, No. 2, pp. 56–57, March–April, 1988.     

Grafting of styrene onto carbon fiber having perester groups

Summary The oxidized carbon fiber having t-butyl perester groups was prepared by the esterification of acid chloride groups on the carbon fiber with t-butyl hydroperoxide. Then, graft polymerization of styrene onto the carbon fiber having t-butyl perester group was carried out. The concentration of monomer affected grafting efficiency. The grafting efficiency increases with the polymerization time and reachs a constant value above 70°C. Addition of Fe ²⁺ and Cu ²⁺ to the polymerization system at a concentration of 0.5–1.0×10 ^-5 mol/l gave the maximum grafting efficiency.     

Selective plasma‐induced grafting of polystyrene onto polyolefin blends

Plasma pretreatment has been used to generate reactive radicals and oxygenated groups on polymer surfaces for graft polymerization. The polymer substrates studied were composed of a polypropylene–polyethylene (PP–PE) copolymer, which was predominantly PP, and also contained blended ethylene–propylene rubber (EPR) as either about 15 or about 60 mol %. A pure PP substrate was also studied for comparison. The grafted polymer was polystyrene (PS). Raman microspectroscopic 2‐dimensional mapping was used to elucidate the role of crystallinity and EPR in the plasma treatment and graft polymerization process. It was found that the plasma pretreatment favored the EPR component of the substrate and the graft yield was related to the EPR content. Crystallinity seemed to have a much less significant effect on the grafting reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1643–1652, 2003     

Effect of the structure of aminoalkyl acrylates on radical graft polymerization to polycaproamide fibre

Graft polymerization of AAMA to PCA fibre was investigated in the presence of the redox system (RDS) Cu_c-H₂O₂. The kinetic and thermodynamic parameters of graft polymerization were determined. The effect of the structure of the monomer on the rate of the process and yield of graft polymer was established. It was found that initiation of graft polymerization of dimethylaminoethyl methacrylate (DMAEMA) and diethylaminoethyl methacrylate (DEAEMA) in the presence of RDS with surface distribution of copper in the fibre causes much higher initial rates of the reaction. The effect of the graft chains in graft polymerization of aminoalkyl methacrylates was determined.Translated from Khimicheskie Volokna, No. 1, pp. 24–26, January–February, 1995.     

马来酸酐固相接枝聚丙烯纤维

了提高非极性聚丙烯纤维(PP)的相容性,采用固相法以马来酸酐(MAH)对聚丙烯纤维进行接枝改性,研究了反应条件对接枝率的影响。结果表明,马来酸酐成功接枝到聚丙烯上,当反应温度为80℃,PP用量为0.5 g,MAH用量为0.2 g,BPO用量为0.05 g,回流时间为2.5 h时,最大接枝率可达到7.51%;BPO的用量、MAH单体的用量以及反应温度对PP纤维的接枝率影响较大。而测定PP纤维接枝率时回流时间对其接枝率的影响不大;接枝聚丙烯纤维的分解温度明显高于纯聚丙烯纤维。     

Dependence of the orientation strengthening of polypropylene fibers on temperature and rate of deformation

Conclusions The mean deformation rate rather fully characterizes the kinematics of polypropylene fiber stretching. It can be used as a norming parameter to obtain generalized temperature-rate characteristics of this process.The degree of orientation in stretching polypropylene fibers, like that for previously studied polymers, is determined by the magnitude of the accumulated highly elastic deformation.Translated from Khimicheskie Volokna, No. 4, pp. 24–25, July–August, 1983.     

Some features of the heterophase emulsion graft polymerization of glycidyl methacrylate to polycaproamide fibre

Conclusions -- The special features of the graft polymerization of glycidyl methacrylate to polycaproamide fibre have been discovered. An anomalous effect of the copper compound and of hydrogen peroxide in the composition of the redox system on the rate of graft polymerization of glycidyl methacrylate has been found.-- The graft polymerization in the presence of the redox system Cu_c-H₂O₂ which has been examined is characterized by a high rate and high monomer conversion and takes place essentially without formation of homopolymer.-- The relationships which have been found indicate a high efficiency and an ecological cleanness of the graft polymerization process at hand.Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 5, pp. 14–16, September–October, 1992.     

Fabrication and properties of modified polyamide fibres in combination of graft polymerization and alkylation

The important possibility of fabricating PCA fibers with improved hygienic properties with a low concentration of polymeric modifier — PDMAEMA quaternary salt — with the reaction of radical graft polymerization in a two-component solution of monomer and alkylating agent was demonstrated. The basic characteristics of graft polymerization of DMAEMA and alkylation combined in the stage of modification of the surface of the fiber-forming polymer were investigated.Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 3, pp. 17–20, May–June, 1994.     

Preparation of cation-exchange polycaproamide fibers

Conclusions -- The process of preparing cation-exchange PCA fibers by the radical graft polymerization of potassium p-styrene-sulfonate in aqueous and in aqueous salt solutions of the monomer has been investigated. The identity of the kinetic parameters (reaction order with respect to monomer and the effective activation energy) of the heterophase graft polymerization of PSS indicates the occurrence of the graft polymerization in the kinetic region.-- A beneficial effect of the nature of the low-molecular electrolyte on the reaction rate and yield of graft polymer has been established; and the optimum content of electrolyte in the reaction mixture has been determined. Cation-exchange fibers have been obtained having an exchange capacity up to 1.3 meq/g.Translated from Khimicheskie Volokna, No. 2, pp. 12–14, March–April, 1993.     

Fabrication of chemisorption amino-containing cellulose fibres

These studies revealed the effect of the polymer matrix on graft polymerization of glycidyl methacrylate. The high efficiency of the Cu_c–H₂O₂ redox system (RDS) in graft polymerization of glycidyl methacrylate (GM) to hydrated cellulose (HC) fibre was demonstrated. Amino-containing HC chemisorption fibres with a SEC of 2.9 meq/g were fabricated.Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 5, pp. 46–49, September–October, 1996.     

Cationic graft polymerization of polymers from carbon fiber initiated by acylium perchlorate groups introduced onto the surface

The cationic graft polymerization of several monomers initiated by acylium perchlorate groups introduced onto the carbon fiber surface was investigated to modify the surface. The introduction of acylium perchlorate groups was successfully achieved by the reaction of silver perchlorate with acyl chloride groups, which were introduced by the reaction of surface carboxyl groups with thionyl chloride. It was found that the cationic polymerization of styrene is initiated by acylium perchlorate groups on the carbon fiber. In the polymerization, polystyrene was grafted onto the carbon fiber surface through the propagation of polystyrene from the surface. Ungrafted polymer was also formed by the chain transfer reaction of growing polymer cation to the monomer. The acylium perchlorate groups have the ability to initiate cationic ring-opening polymerization of tetrahydrofuran (THF) and ε-caprolactone (CL), polyTHF and polyCL being grafted onto the carbon fiber surface, respectively. Polyacetals, such as poly(1,3-dioxolane) and polyoxymethylene, were able to graft onto the carbon fiber by cationic ring-opening polymerization of the corresponding monomers.     

Failure of polypropylene fibers

Conclusions A quantitative definition of the highly elastic deformation built up in extension of polypropylene fiber has been proposed.In the extension of a crystallizing polymer, under definite temperature-deformation conditions, a steady flow regime is reached (analogous to amorphous polymers). Under these conditions, breakage takes place on reaching a critical fiber diameter, regardless of the original fiber thickness.Translated from Khimicheskie Volokna, No. 4, pp. 22–23, July–August, 1983.     

Carbochain ion-exchange fibres prepared by the graft polymerization method

Conclusions A comparative analysis has been made of the laws governing the process of graft polymerization of partially hydrolyzed PAN fibres with monomers of ionogenic and nonionogenic character.It has been shown that the activity of the investigated monomers in graft polymerization reactions and their effective conversion are reduced, as a rule, with increase in the charge of the monomer, and the homopolymer content is increased.In selecting optimum conditions for a graft polymerization as a method of preparing fibrous ion-exchangers, along with the yield of graft copolymer and the effective conversion, one should also take into account the proportion of active functional groups in the graft copolymer.Leningrad Institute of Textile and Light Industry. Translated from Khimicheskie Volokna, No. 1, pp. 19–22, January–February, 1987.     

Radiation synthesis of polypropylene-acrylate grafted fiber and its remediation in the spillage of water-insoluble organic chemicals

A new kind of functionalized polypropylene(PP)-acrylate grafted fiber were prepared by radiation-induced graft polymerization of methyl acrylate (MA), ethyl acrylate(EA) and butyl acrylate (BA) monomer onto the PP fiber matrix, as a recovery adsorbent for insoluble organic chemicals. The grafting conditions of monomer concentration and irradiation time on the grafting degree were optimized. The obtained grafted fiber sample was identified by Fourier transform infrared (FT-IR) spectrometer and scanning electron microscopy (SEM) to characterize the chemical and morphological changes of the polypropylene fiber surface. The adsorption results indicated that the grafted fiber could be used to remove organic chemicals from water surface. The adsorption capacity of grafted fiber with different acrylate monomer was obviously different for the same chemicals, therefore, investigations with respect to organic removal, dynamic oil retention, and reusability, the effect of monomer polarity on the adsorption capacity of grafted fiber was especially highlighted in this study.     

Graft polymerization of propylene sulfide on crosslinked polystyrene

Sulfur containing graft polymers that may be of interest as polymeric transfer agents were synthesized. Graft polymerization of propylene sulfide on crosslinked polystyrene beads was investigated; both crosslinked polystyrene and its chloromethylated derivative were grafted. Crosslinked polystyrene was metallated by BuLi–TMEDA and was used to initiate anionic graft polymerization of propylene sulfide. Graft polymers of high polypropylene sulfide content corresponding to 10 mmol s/g were obtained. The grafted polypropylene sulfide was evenly distributed across the bead cross section. No change in bead surface characteristics was observed. Grafting on chloromethylated polystyrene beads was achieved by reaction between the chloromethylene groups with sulfide groups of performed polypropylene sulfide, and with terminal sodium thiolate groups of living polypropylene sulfide.     

Solid‐phase grafting of hydroxymethyl acrylamide onto polypropylene through pan milling

The solid‐phase graft polymerization of hydroxymethyl acrylamide (HMA) onto polypropylene (PP) was realized by employing our self‐designed pan‐type milling equipment which has a unique and smart structure and can exert quite strong shear forces and pressure on the materials in between and break them down. When PP particles and HMA are pan‐milled together, the macromolecular radicals generated from the chain scission of PP under stress can initiate HMA to polymerize, forming the PP‐g‐HMA graft copolymer. The graft copolymers were characterized by chemical titration, FTIR, DSC, and contact angle measurement. The amount of grafted HMA depends on the HMA concentration, increase of the PP particles' surface area during pan milling, temperature, as well as rotation speed of the mill pan. The percentage of grafting reaches 2.43%. The particle‐size analysis showed that PP with a larger particle size favors the graft polymerization of HMA onto PP. DSC analysis demonstrated that the crystallinity of PP‐g‐HMA decreases as compared with PP due to the grafting of HMA onto PP. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2191–2197, 2000     

Durable,hydrophilic surface modification of polypropylene films by plasma graft polymerization of glycidyl methacrylate

Summary The plasma graft polymerization of glycidyl methacrylate (GMA) was investigated to obtain hydrophilic surface. The combination of the argon plasma and GMA vapor exposures leaded to graft polymerization of GMA at the surface of polypropylene films. This graft polymerization was initiated by the argon plasma exposure for 2 min, and was accomplished with the GMA vapor exposure for 2 min. The GMA graft polymerization made polypropyrene surface hydrophilic. The surface energy was 55.8 mJ/m². The hydrophilicity introduced by the GMA graft polymerization remained for at least 3 weeks. The graft polymerization of hydrophilic monomers was a good means of hydrophilic surface modification.