Polymers from renewable resources. II. A study in the radio chemical grafting of poly(styrene‐alt‐maleic anhydride) onto cellulose extracted from pine needles

A binary mixture of styrene and maleic anhydride has been graft copolymerized onto cellulose extracted from Pinus roxburghii needles. The reaction was initiated with gamma rays in air by the simultaneous irradiation method. Graft copolymerization was studied under optimum conditions of total dose of radiation, amount of water, and molar concentration previously worked out for grafting styrene onto cellulose. Percentage of total conversion (Pg), grafting efficiency (%), percentage of grafting (Pg), and rates of polymerization (R_p), grafting (R_g), and homopolymerization (R_h) have been determined as a function of maleic anhydride concentration. The high degree of kinetic regularity and the linear dependence of the rate of polymerization on maleic anhydride concentration, along with the low and nearly constant rate of homopolymerization suggest that the monomers first form a complexomer which then polymerizes to form grafted chains with an alternating sequence. Grafting parameters and reaction rates achieve maximum values when the molar ratio of styrene to maleic anhydride is 1 : 1. Further evidence for the alternating monomer sequence is obtained from quantitatively evaluating the composition of the grafted chains from the FT‐IR spectra, in which the ratio of anhydride absorbance to aromatic (CC) absorbance for the stretching bands assigned to the grafted monomers remained constant and independent of the feed ratio of maleic anhydride to styrene. Thermal behaviour of the graft copolymers revealed that all graft copolymers exhibit single stage decomposition with characteristic transitions at 161–165°C and 290–300°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1763–1769, 1999     

Thermal studies of copolymers of styrene and maleic anhydride

Copolymers of styrene and maleic anhydride prepared by a charge transfer mechanism have been studied thermally by thermogravimetry and differential scanning calorimetry. The copolymers degrade in two stages; the first stage accounts for about 85% of the degradation. Incorporation of maleic anhydride to styrene decreases the thermal stability of the later. Differential scanning calorimetric studies show two exotherms between 300° to 500 °C. Glass-transition temperatures for the copolymers are lower than that of polystyrene.     

Developments in the synthesis of maleated polyolefins by reactive extrusion

The maleation of conventional and metallocene linear low density polyethylenes by reactive extrusion has been explored with a view to defining the conditions necessary for a robust process that provides both high grafting efficiencies (>80%) and minimal degradation or cross-linking. The dependence of grafting efficiency on various operating parameters (maleic anhydride level, maleic anhydride:initiator ratio, throughput rate, direction of screw rotation, temperature) has been established. Literature methods for characterization of the grafted product based on FTIR or ¹H NMR analysis have been critically examined with respect to their ability to distinguish between single unit and oligomeric maleic anhydride grafts and found to yield ambiguous results.     

On the role of monomer—monomer donor—acceptor complexes in the free-radical copolymerisation of styrene and maleic anhydride

The kinetics of the free-radical copolymerisation of styrene and maleic anhydride at 60° in bulk and in several solvents have been studied. Copolymer compositions may be interpreted either in terms of a mechanism involving a penultimate group effect or in terms of a mechanism involving some propagation via styrene—maleic anhydride donor—acceptor complexes. However, experiments at various overall monomer concentrations and in which zinc chloride and phthalic anhydride have been added indicate that the penultimate group effect mechanism is to be preferred.     

马来酸酐-苯乙烯熔融接枝聚丙烯的影响因素及其性能研究

用单螺杆挤出机制备了马来酸酐 (MAH) 苯乙烯 (St)对聚丙烯 (PP)的多组分单体自由基熔融接枝体系 .研究证实了当两种单体物质的量比约为 1∶1时 ,接枝物的接枝率最高 ,而熔体流动速率 (MFR)最大 .对反应体系影响因素的研究表明单体用量和引发剂用量对不同单体用量比的系列接枝物的接枝率会产生不同的影响 ;另外 ,单体用量增加 ,接枝物的MFR减小 ,过氧化二异丙苯 (DCP)用量增加 ,接枝物的MFR增加 .对多单体熔融接枝聚丙烯PP g (MAH co St)的力学性能研究发现 ,选用合适的单体用量比、单体用量和DCP用量时 ,所制备的接枝物可具有与纯PP相当或更佳的力学性能     

Controlled “Grafting-from” of poly[styrene-co-maleic anhydride] onto polydienes using nitroxide chemistry

High-throughput experimentation was used for the functionalization of polybutadiene and polyisoprene with several kinds of nitroxide moieties at 135 °C, as well as for kinetic investigations of the controlled free radical grafting of styrene and maleic anhydride onto the functionalized polydienes at 125 °C. The functionalized polymers were analyzed by GPC, ¹H NMR and FT-IR and the control of the grafting process was assessed by kinetic measurements and GPC analysis. The best control in the molecular weight of the grafts was observed for the polydienes functionalized with 4-oxo-TEMPO. TEMPO functionalization did not render sufficient nitroxide moieties to achieve controlled grafting, while polydienes functionalized with other 4-hydroxy TEMPO derivatives exhibited some level of grafting control at early reaction times, which was lost in later stages of the polymerization reaction. SG1 apparently decomposed at the tested reaction temperatures, as polydienes functionalized with SG1 did not show any level of control during the grafting process.     

A study of the relative reactivity of maleic anhydride and some maleimides in free radical copolymerization and terpolymerization

Composition data for the free radical copolymerization of maleic anhydride with N-phenylmaleimide in toluene at 60°C have been obtained. Relative reactivity ratios in terminal and penultimate models using nonlinear least-squares optimization routine have been determined. The standard error was found to be somewhat smaller in the penultimate model, but is still larger than the uncertainty estimated for the copolymer composition. Terpolymers of maleic anhydride and styrene with maleimide, N-butylmaleimide, N-phenylmaleimide, and N-carbamylmaleimide were obtained. On the basis of analysis of the product composition at various monomer feeds the relative reactivity of maleic anhydride and maleimides in these reactions is compared and the influence of the structure of thesemonomers on the rate of some chain growth reactions is discussed.     

Peroxide-initiated grafting of maleic anhydride onto linear and branched hydrocarbons

The structural features of the grafting of maleic anhydride onto low-molecular-weight compounds have been elucidated using several spectroscopic and analytical techniques. Conclusive evidence for the occurrence of singly grafted anhydride residues in multiply grafted products has been established using 2,3-¹³C₂ labeled maleic anhydride. In homogeneous solution, at the low concentrations of maleic anhydride employed, there is little evidence for oligomeric or polymeric grafts to dodecane, pristane, or squalane. The results suggest that isothermal grafting of maleic anhydride to hydrocarbon polymers should also lead to a predominance of single grafts. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3817–3825, 1999     

An ESR Study of the UV Photolysis of Styrene and Maleic Anhydride at 90 K

Free radicals produced in styrene and maleic anhydride mixtures and in solutions in acetone and chloroform by UV photolysis at 90 K have been studied by electron spin resonance and changes observed on warming. A doublet spectrum observed in all systems containing maleic anhydride has been assigned to the radical formed by H addition to a carbonyl group in the monomer, and not to the corresponding radical on maleic anhydride units in the copolymer or to the maleic anhydride propagating radical. Interpretations of copolymerization mechanisms based on radicals produced in frozen comonomers in bulk or in solution by photolysis or radiolysis must therefore be viewed with caution.     

Peroxide-initiated crosslinking of maleic anhydride-modified low-molecular-weight polybutadiene. I. Mechanism and kinetics of the reaction

The crosslinking mechanism and kinetics of low-molecular-weight polybutadiene, its mixtures with maleic anhydride, and the products of its grafting with maleic anhydride and styrene, using dicumyl peroxide (DCP) as an initiator, were studied. It was shown that for all systems crosslinking is a radical polymerization of the double bonds. Modification of polybutadiene changes only the kinetic parameters of the crosslinking reaction and causes mainly a decrease of the termination step velocity. From DSC data the crosslinking reaction order, activation energy, and reaction heats were calculated.     

Reactive polymers on the basis of functional peroxides

The copolymerization constants of new monomer containing ditertiary peroxide groups with styrene have been determined. The peroxide monomers were prepared by the acylation of 3-(tert-butylperoxy)-3-methyl-1-butanol with methacryloyl chloride or maleic anhydride in the presence of tertiary amines. Peroxide containing copolymers were obtained by copolymerization of peroxyalkyl methacrylate and peroxyalkyl maleate with styrene.     

Studies on the Crystallization Behavior of Polypropylene Solid Phase Grafted Maleic Anhydride

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Shell-crosslinked nanostructures from amphiphilic AB and ABA block copolymers of styrene-alt-(maleic anhydride) and styrene: polymerization, assembly and stabilization in one pot

Shell-crosslinked nanostructures having unusual rosette morphologies have been produced by a simple process from styrene and maleic anhydride.     

超临界二氧化碳体系中PVDF微孔膜的表面接枝改性

超临界二氧化碳（SCCO2）是一种T〉31．1℃,P〉7．38MPa的二氧化碳流体,不仅具有类似于气体的粘度和类似于液体的密度,而且可以通过改变温度或压力控制SCCO2的密度及溶解性．SCCO2对有机小分子具有优良的溶解、扩散和渗透性能,化学惰性,无污染,易于分离,作为一种聚合反应介质,受到学术界日益增多重视．SCCO2极低的粘度使其具有良好的流动性和扩散渗透性能,零表面张力使其对聚合物具有良好的润湿和增塑性,这将促进引发剂和聚合单体向微孔膜的外表面及内表面扩散．利用温度和压力改变SCCO2的溶解性能调整单体在聚合物相和SCCO2相之间的分布,进而控制微孔膜内外表面的接枝程度．所以SCCO2接枝聚合反应对于聚合物膜的表面改性具有极其重要的意义．     

稀土配位催化马来酸酐-苯乙烯-N-苯基马来酰亚胺三元共聚合

采用稀土配位催化剂研究了马来酸酐、苯乙烯和N 苯基马来酰亚胺的三元共聚合反应 .考察了Al La物质的量的比、不同稀土元素、催化剂浓度、聚合反应时间、单体配比等因素对共聚合反应的影响 .利用核磁、红外、热分析等方法对共聚物进行了初步的表征     

Dual monomer grafting of styrene and maleic anhydride onto model hydrocarbon substrates

Styrene and maleic anhydride (MAn) were successfully grafted, alone and simultaneously, onto various model hydrocarbon substrates at 180 °C with 2,5‐dimethyl‐2,5‐di‐(t‐butyl peroxy)hexane (L101) as a free‐radical initiator. Dodecane, 1‐dodecene, and 2,6,10,14‐tetramethylpentadecane were selected as model compounds to investigate the effects of terminal unsaturation and branching on grafting and crosslinking. These compounds were chosen to mimic the aforementioned microstructural characteristics that are commonly observed in polyethylene. The results demonstrate that terminal unsaturation increases the amount of crosslinked material in the presence of L101. With respect to grafting, for the single monomer systems, MAn prefers to graft as single saturated units, whereas styrene prefers to graft as long chains of polystyrene oligomers. However, when both monomers are grafted simultaneously, graft yields are drastically reduced because of a propensity for the two monomers to form a styrene–maleic anhydride copolymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2456–2468, 2000     

Contribution to the study of the mechanism of curing of unsaturated polyester resins

The mechanism of copolymerization of monomethyl and dimethyl maleates and fumarates with styrene was studied by analysis of the conformation of the acid units of the resulting copolymers. The absorption bands for C?O stretching and OH stretching in the spectra of the copolymers are fully identical. They are quite different from the spectra of the copolymers obtained from maleic anhydride and styrene that are subsequently treated with absolute methanol to give the monoester which is then esterified with diazomethane to give the diester. The acid units of the copolymers derived from maleic anhydride exist in a gauche configuration; copolymers derived from fumaric units exist in a trans conformation. The identity of copolymers derived from maleic units with those derived from fumaric units but not with those derived from maleic anhydride indicates that the first step in the copolymerization of the maleic units is an isomerization to fumaric units, which are actually the genuine comonomers.     

Polymerization initiated by the charge-transfer complex of styrene and maleic anhydride in the presence of cumene and of cumene and liquid sulfur dioxide

A polymerization was induced with a charge-transfer type of complex consisting of styrene and maleic anhydride in the presence a solvent such as ethyl benzene, cumene, or p-cymene. No polymer was obtained either when the solvent was missing from the polymerization system or when benzene, toluene, or xylene, which are relatively stable to hydrogen abstraction, was added to the polymerization system. An effective initiation, however, took place when cumene or p-cymene, each of which has a labile hydrogen on an α carbon, was added. On the basis of elementary analysis and infrared spectroscopy the formation of copolymer containing substantially equimolar amounts of styrene and maleic anhydride was ascertained. This polymerization was inhibited by the addition of DPPH, suggesting that the system styrene–maleic anhydride–cumene functions much as a conventional free-radical initiator. On the other hand, when a solution of cumene and liquid sulfur dioxide was added to the polymerization system, polystyrene was obtained. This polymerization was inhibited by the addition of a base such as dimethyl-formamide or dimethyl sulfoxide, indicating that the polymerization proceeds through carbonium ion intermediates. The addition of ethyl benzene or of p-cymene brought about the same result as cumene. It is conceivable that the polymerization is induced by the abstraction of hydrogen attached at the α position of cumene by means of the charge-transfer complex of styrene and maleic anhydride.     

马来酸酐接枝聚丙烯的改性方法及其应用

马来酸酐(MAH)是聚丙烯改性中最常用的极性单体,在连续反应中酸酐基呈现很高的活性,反应产物热稳定性良好,可被应用于合金,塑料等材料的生产。随着各种技术的广泛应用,马来酸酐接枝聚丙烯改性方法得到了快速的发展。各种马来酸酐接枝聚丙烯的改性方法有:溶液接枝法、熔融接枝法、固相接枝法和辐射接枝法。文章阐述了马来酸酐接枝聚丙烯改性方法的研究现状及其产物在不同领域的应用。     

Penultimate effects in the copolymerization of maleic anhydride with electron‐rich styrene derivatives

The (controlled) free‐radical copolymerization of maleic anhydride and styrene or derivatives thereof is often thought to provide nearly perfect alternating copolymers. Here, the RAFT copolymerization of electron‐rich styrene derivatives with maleic anhydride is reported. This copolymerization shows distinct penultimate effects, resulting in polymers with increased incorporation of styrene monomers, that is, where a tendency toward periodic (S‐S‐MA) copolymers exists. This work could be a first step towards periodic copolymers based on maleic anhydride and styrene derivatives. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2932–2939