悬浮接枝共聚合成POE-g-MAS及其表征

用悬浮接枝法合成了乙烯-辛烯共聚物（POE）和甲基丙烯酸甲酯（MMA）-丙烯腈（AN）-苯乙烯（St）的接枝共聚物（POE-g-MAS）。研究了单体比率、POE／单体的比率、引发剂浓度和反应时间等因素对接枝共聚合反应的影响。从聚合产物中用丙酮抽提得到接枝共聚物POE-g-MAS,并用傅立叶变换红外光谱（FTIR）和差示扫描量热法（DSC）对POE-g-MAS进行了分析。实验证明MMA-AN-St已经接枝在POE分子链上。接枝链MAS在一定程度上影响了POE的结晶相,降低了POE的熔融温度和熔融热。     

悬浮接枝共聚合成POE-g-MAS及其对SAN树脂的增韧作用

合成了乙烯-辛烯共聚物(POE)和甲基丙烯酸甲醋(MMA)-丙烯腈(SAN)-苯乙烯(St)的接枝共聚物(POE-g-MAS)。研究了单体比率、POE/单体比率和引发剂浓度等因素对接枝共聚合反应的影响。聚合产物用丙酮抽提得到接枝共聚物POE-g-MAS,傅里叶变换红外光谱分析证明MMA-AN-St已经接枝在POE分子链上。用POE-g-MAS与Stet树脂共混制备了具有高抗冲性能的POE-g-SAN/SAN共混物,并用扫描电镜观察共混物的冲击断面,探讨了其增韧机理。     

Graft copolymerization of vinyl monomers on cellulosic materials

Graft copolymers of acrylonitrile, ethyl acrylate, methyl acrylate, ethyl methacrylate and methyl methacrylate and of acrylonitrile/ethyl methacrylate and acrylonitrile/methyl methacrylate monomer mixtures on carboxymethylcellulose (degree of substitution 0.4–0.5) were prepared by use of ceric ion initiator in aqueous medium. The extent of graft polymer formation was measured in terms of graft level, molecular weight of grafted polymer chains and frequency of grafting as function of ceric ion concentration. It was found that at comparable reaction conditions, the molecular weight and frequency of grafting were not of the same order of magnitude. For the monomer mixtures, the copolymer compositions obtained from the total nitrogen content of the acrylonitrile/alkyl methacrylate copolymer samples showed that a relativity low amount of the acrylonitrile monomeric units were incorporated into the graft copolymer even at high acrylonitrile content of the feed.     

Graft polymerization of triethoxyvinylsilane–styrene and triethoxyvinylsilane–methyl methacrylate binary monomers onto various silicates

Triethoxyvinylsilane–styrene and triethoxyvinylsilane–methyl methacrylate binary monomers were polymerized by chemical initiation or by γ-ray irradiation in the presence of silica gel, fire brick, quartz wool, and glass beads. The amount and composition of the polymers grafted to silicates were analyzed by using pyrolysis gas chromatography. When triethoxyvinylsilane alone was subjected to the reaction with silicates, condensation occurred irrespective of the initiating means, and the extent of the reaction was almost proportional to the specific surface area of the silicate. When binary monomer mixture was applied, incorporation of styrene or methyl methacrylate into the grafted polymer was observed whenever a monomer mixture of high styrene or methyl methacrylate content was submitted to the reaction. On each silicate, the relationship between the composition of polymer grafted on it and that of monomer showed a similar pattern in spite of the great difference of the specific surface area. Almost no participation of styrene or methyl methacrylate was observed when the silicate preirradiated in air or under vacuum was heated with the binary monomer mixture. It was concluded that triethoxyvinylsilane reacts with silicates by condensation and that some of the pendent vinyl groups on the silicates are incorporated into the copolymer with styrene or methyl methacrylate.     

Studies in the graft copolymerization of vinyl monomers on cellulosic materials

Graft copolymerization of acrylonitrile, methyl methacrylate, and vinyl acetate on bleached holocellulose initiated by ceric ions in aqueous medium was studied at 29°C. The extent of graft copolymer formation was poly(methyl methacrylate) > polyacrylonitrile > poly(vinyl acetate), indicating the influence of polarity of monomer on graft copolymerization. It was found that, although the molecular weights of the grafted polyacrylonitrile copolymer were lower than the values obtained for poly(methyl methacrylate), the latter was less frequently incorporated on the cellulosic backbone polymer than the polyacrylonitrile grafts. The marked reductions in graft level associated with thiolation of the cellulosic material suggest that hydrogen abstraction reactions from carbon atom carrying hydroxyl groups may not be important in graft copolymer formation.     

Graft copolymerizations of modified cellulose,grafting of acrylonitrile,and methyl methacrylate on carboxy methyl cellulose

Graft copolymers of acrylonitrile (ACN), methyl methacrylate (MMA), and their mixtures on carboxy methyl cellulose (d.S 0.4–0.5) were prepared by the use of ceric ion initiator in aqueous medium. The graft copolymers were characterized by IR spectroscopy. The extent of graft copolymerization of ACN and MMA was measured in terms of graft level, molecular weight of grafted polymer chains, and the frequency of grafting as functions of ceric ion concentration. It was found that at comparable reaction conditions, the molecular weight of the grafted polymer chains and the frequency of grafting were not of the same order of magnitude. For the monomer mixtures, the copolymer compositions obtained from the total nitrogen contents of the copolymer samples showed that a disproportionately low amount of ACN monomeric units were incorporated into the graft copolymer, even at high ACN content of the feed. © 1996 John Wiley & Sons, Inc.     

Polymerization initiated with polymeric compounds,II

The polymerization of methyl methacrylate initiated by the copolymers methacrylaldehyde — styrene — divinylbenzene and acrylaldehyde — ethylene dimethacrylate in the absence of usual initiators was investigated. The polymerization was found to proceed fairly readily and fast. Acceleration can be achieved by adding glycerylaldehyde. An increase in the surface of the initiating copolymer favourably influences the reaction rate; at the same time, however, physical trapping of ungraft poly(methyl methacrylate) molecules in the macroporous initiator seems likely to occur. It was also found that only copolymers containing aldehyde groups could be used for initiation and that besides MMA some other monomers could be polymerized in this way, such as glycidyl methacrylate, acrylic and methacrylic acid, acrylonitrile, and alkyl acrylate.     

Improvement of the mechanical stability of oak by radiation-induced in-situ copolymerization of allyl glycidyl ether with acrylonitrile and methyl methacrylate

This study deals with the improvement of the mechanical stability of oak, which belongs to the hardwoods, by radiation-induced in-situ copolymerization of certain monomers. Acrylonitrile (AN), methyl methacrylate (MMA), allyl glycidyl ether/acrylonitrile (AGE/AN), and allyl glycidyl ether/methyl methacrylate (AGE/MMA) monomers and monomer mixtures were employed to conserve and consolidate the wood. After impregnating oak with these monomer mixtures, polymerization was accomplished by γ-irradiation. The relationships between the mechanical properties of the wood/(co)polymer composites and the anatomic structure of the wood, the types and the quantity of the polymer and copolymer, the irradiation dose and the aging process were explored. The fine structure of the wood/(co)polymer composites and the compatibility of wood with polymer and copolymer were investigated by scanning electron microscopy. The existence of polymer and copolymer in the wood enhanced the mechanical durability of the wood. The results of the hardness and the compressive strength tests applied in the parallel and perpendicular directions to the fibers of the wood/(co)polymer composites show that P(AGE/MMA), P(AGE/AN) copolymers are effective in raising the mechanical durability. In the case of P(AGE/MMA), the increase in the compressive strength perpendicular to the fibers in the oak wood is 179% at highest conversion. Similar results were also acquired from hardness tests. The decrease in the mechanical durability after aging for 28 d was very little.     

Graft copolymerization of acrylonitrile and methyl methacrylate monomer mixtures on crumb natural rubber

Graft copolymerization of mixtures of acrylonitrile and methyl methacylate on crumb natural rubber was carried out in toluene at 60°C. The nitrogen content of the grafted copolymer was determined by elemental analysis and used to estimate the composition of the copolymer samples. It was found that the amount of acrylonitrile monomeric units incorporated into the polymer was disproportionately lower than the acylonitrile content of the feed and explanations in terms of the e‐value of the monomers and the inherent heterogenous nature of the polymerization mixture were offered. The miscibility of the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) with poly(vinyl chloride) was studied by viscometry, differential scanning calorimetry, and phase contrast microscopy. It was found that the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) formed semimiscible blends with poly(vinyl chloride). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1872–1877, 2002; DOI 10.1002/app.10474     

乙丙橡胶接枝改性技术

综述了以苯乙烯、丙烯腈、马来酸酐、甲基丙烯酸缩水甘油酯、甲基丙烯酸甲酯、乙酸乙烯酯及硅烷偶联剂为接枝单体的乙丙橡胶接枝改性技术，包括溶液接枝法、熔融接枝法、直接溶胀接枝法以及近年来最新的电子束辐射接枝和热炼接枝等接枝方法。     

Vapor phase photografting on low-density polyethylene film in binary monomer systems

Vapor phase photografting of monomer mixtures on low-density polyethylene film, on which benzoyl peroxide is coated, was investigated at 60°C using various vinyl, allyl, and solid monomers. Styrene (St) itself was difficult to graft on the film substrate, but the combinations of St with vinyl monomers such as acrylonitrile (AN), glycidyl methacrylate (GMA), acrylic acid, and methacrylic acid led to the accelerated grafting, affording a maximum percent grafting at an certain monomer ratio. The same combination effect was observed for AN–N-vinyl pyrrolidone and –GMA monomer mixtures. The monomer combinations such as allyl aldehyde–St and allyl alcohol–maleic anhydride were useful for performing the grafting of allyl monomers effectively. Maleic anhydride and maleimide as solid monomers were also possible to introduce into the film substrate by means of the monomer combination, where St, N-vinyl pyrrolidone, vinyl ethers, and benzyl methacrylate were available as comonomers. Thus, the monomer combinations affording an accelerating effect on grafting may be monomer pairs rich in an alternative copolymerizability, suggesting that monomer reactivity ratio controls a major factor for the combination effect. It was confirmed from IR study on grafted films that both monomer components are introduced in the film substrate as the grafted chain component.     

Phase separation of some clear polyblends

By using variations of elution and precipitation techniques, a clear ABS resin is found to be a mixture of a styrene–butadiene rubbery copolymer, a methyl methacrylate–styrene–acrylonitrile copolymer, and a graft of the methyl methacrylate–styrene–acrylonitrile copolymer onto the styrene–butadiene rubber. A clear impact acrylic is separated into a methyl methacrylate–styrene–acrylonitrile copolymer and a methyl methacrylate–butadiene rubbery copolymer. Photomicrographs indicate that clarity in the clear ABS and impact acrylic is achieved by matching refractive indices of the continuous and dispersed polymer phases.     

Modification of some mechanical properties of spruce by radiation induced copolymerization of acrylonitrile and methyl methacrylate with allyl glycidyl ether

In this study, spruce samples were impregnated with acrylonitrile (AN), methyl methacrylate (MMA), allyl glycidyl ether (AGE), AGE/AN or AGE/MMA monomers and monomer mixtures. In situ polymerization (copolymerization) was achieved by gamma irradiation. The relationship between the mechanical properties of the wood‐polymer(copolymer) composites and the kind and quantity of polymers and copolymers, irradiation dose and artificial aging treatment of the wood was investigated. The fine structure of wood‐polymer(copolymer) composites was determined by Scanning Electron Microscopy. The presence of homopolymer and copolymers increased the mechanical properties of the wood. The compressive strength and Brinell Hardness Numbers, determined for untreated and treated wood samples, indicated that the mechanical strength of wood‐polymer (copolyrner) was significantly increased in the presence of P(AGE/MMA). At maximum percent conversion, the percentage increase in the compressive strength with regard to the applied force perpendicular to the fibers in spruce was 218%. After aging for 28 days, it was found that there were no significant changes in mechanical stability.     

Thermal behavior of cotton grafted with vinyl monomers individually and in mixture compositions

Thermal analysis of cotton samples grafted with acrylamide, acrylonitrile, methyl acrylate, and methyl methacrylate individually and in mixture compositions has been carried out. Additional endothermic peaks in the DTA curves characteristic of the polymers grafted were observed. Graft copolymerization of acrylamide and acrylonitrile makes cotton thermally more stable, while in the case of methyl acrylate-and methyl methacrylate-grafted cottons, the initial decomposition starts at higher temperatures, but subsequent decomposition is faster and the overall thermal stability is lowered. In the case of binary mixtures of acrylamide and acrylonitrile, inception of decomposition starts earlier, but subsequent decomposition takes place at much higher temperatures than for individual monomer-grafted cottons. Interaction between monomers during grafting is indicated. When fabric samples containing polyacrylamide grafts are methylolated and subsequently cross-linked, there is a reduction in the thermal stability of the treated cotton.     

A new copolymerization equation

A new copolymerization equation is suggested for the calculation of copolymer composition. The new equation is independent of reactivity ratios, so we can obtain the copolymer composition from experimental data when the reactivity ratios are unknown. The new equation has been verified by experimental data (styrene/methyl methacrylate, methyl methacrylate/vinyl chloride, and styrene/acrylonitrile systems). The results of the comparisons suggest that the new equation is satisfactory. © 1995 John Wiley & Sons, Inc.     

Reactivity ratios during radiation‐induced grafting of comonomer mixtures onto polyester fabrics

Radiation‐induced grafting of binary mixtures of acrylonitrile (AN)/styrene (S) and acrylamide (AAm)/styrene (S) onto polyester fabric (PET) has been investigated. Synergism during radiation grafting was investigated by determining the graft yield fraction for each monomer in the final graft copolymer. Moreover, by knowing the mole fraction of each monomer in the grafting solution, the reactivity ratio of the individual monomers in the comonomer mixture during graft copolymerization could be determined: in the case of AN/S comonomer mixture, the calculated reactivity ratios for AN and S are 0.04 and 0.05, respectively; the calculated reactivity ratios of AAm and S in their comonomer mixture are 1.82 and 0.41, respectively. © 2001 Society of Chemical Industry     

EPDM-g-MAN的合成及AEMS的冲击性能研究

用(乙烯/丙烯/二烯)共聚物(EPDM)与甲基丙烯酸甲酯(MMA)、丙烯腈(AN)进行溶液接枝共聚合成了(EPDM/MMA/AN)接枝共聚物(EPDM-g-MAN),并将其与(苯乙烯/丙烯腈)共聚物(SAN)共混制得高抗冲耐老化黄变性能优异的EPDM-g-MAN/SAN共混物(AEMS).研究了AN用量对不同EPDM-g-MAN接枝体系单体转化率(CR)、接枝率(GR)、接枝效率(GE)及AEMS缺口冲击强度的影响.结果发现,随着AN用量的增加,EPDM-g-MAN的CR逐渐下降;GR、GE在AN质量分数为5%时出现最大值;AEMS的缺口冲击强度均在AN质量分数为10%时出现最大值,为61.0 kJ/m2;EPDM相以条状形态构成的近连续相结构存在,径向尺寸较小的EPDM条形结构能诱发SAN基体剪切屈服,径向尺寸较大的EPDM条形结构仅能诱发基体空穴化.     

Organotin polymers. IV. Binary and ternary copolymerizations of tributyltin acrylate and methacrylate with styrene,allyl methacrylate,butyl methacrylate,butyl acrylate,and acrylonitrile

The monomer reactivity ratios for the copolymerization of tributyltin acrylate with styrene and allyl methacrylate have been found to be r₁ = 0.213, r₂ = 1.910 and r₁ = 0.195, r₂ = 2.257, respectively. Also, the copolymerization parameters of tributyltin methacrylate with styrene and allyl methacrylate were as follows: r₁ = 0.256, r₂ = 1.104 and r₁ = 2.306, r₂ = 1.013. Copolymerization reactions were carried out in solution at 70°C using 1 mole % AIBN, and the copolymer compositions were determined by tin analysis. Ternary copolymerization of the three systems butyl methacrylate–tributyltin methacrylate–acrylonitrile, butyl acrylate–tributyltin methacrylate–acrylonitrile, and styrene–tributyltin acrylate–acrylonitrile have been studied, and the terpolymer composition of each system was determined through tin and nitrogen analyses. The variation of instantaneous and average terpolymer composition with conversion fit satisfactorily the experimental results over a wide range of conversion.     

Grafting of acrylonitrile and methyl methacrylate from their binary mixtures on cellulose using ceric ions

Ceric ion‐initiated grafting on cellulose from a binary mixture of acrylonitrile and methyl methacrylate was carried out in heterogeneous and acidic conditions at 30 ± 0.1°C in a nitrogen atmosphere. To avoid the complexation of water molecules with Ce(IV) ions, the concentration of the nitric acid was taken to be more than the concentration of ceric ions. The effect of the feed concentration, reaction time, and ceric ions concentration on grafting were investigated at a fixed composition. To investigate the effect of monomer–monomer interactions on grafting, the graft copolymerization was also studied, using different feed compositions (f_AN) ranging from 0.25 to 0.80. In this range of feed composition, the synergistic effect of methyl methacrylate molecules has shown an important effect on acrylonitrile monomer and facilitate the incorporation of the acrylonitrile monomer into the grafted chains. The reactivity ratios of acrylonitrile and methyl methacrylate were calculated using the Mayo and Lewis method and were found to be 0.74 and 1.03, respectively. The average sequence lengths of the monomers (m̄M) were found to be dependent on the feed compositions and found to be arranged in alternate fashion in the grafted chains. The probability of the addition of a monomer (P_1,1) to the growing radicals on cellulose ended with its own type of monomer was found to be dependent on the feed composition. The composition of the grafted copolymers, homocopolymers, was determined by IR and elemental analysis for nitrogen. None of the grafted chain on cellulose was found to be made of a single type of monomer. The ceric ion consumption during grafting was found to be independent of the molarity of the feed but shown an appreciable change in the initial few hours of grafting. The variation in the values of the grafting parameters as a function of the reaction conditions is suitably explained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 767–778, 2001     

Self‐driven graft polymerization of vinyl monomers on poultry chicken feathers in the absence of initiator/catalyst

An efficient and simple method for graft copolymerization of powdered chicken feather (CF) with vinyl monomers without any free radical initiator is reported. Various vinyl monomers such as glycidyl methacrylate (GMA), styrene (S), and methyl methacrylate (MMA); (20–60 wt % with respect to CF) were successfully grafted to chicken feather (CF) by using sodium dodecyl sulfate (SDS, 0.086–0.5 mmol) in the absence of any catalyst or initiator. Most likely, the hydrophilicity, hydrophobicity, and complex forming properties of chicken feather keratin with surfactant molecules were responsible for efficient grafting of polymers on CF surface. The effect of polymerization conditions, such as monomer concentration, temperature, and time of reaction, on the grafting parameters such as monomer conversion, grafting efficiency, and molar grafting ratio were studied. The described method showed a good potential of using low cost, easily accessible poultry chicken feathers as grafting material and self catalyzing agent for graft copolymerization with vinyl monomers to produce low cost commodity plastic for various end uses. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44645.