高交联大孔苯乙烯—二乙烯苯共聚物的磺化反应

研究了高交联大孔苯乙烯－二乙烯苯共聚物在有溶胀剂和无溶胀剂条件下,反应温度、反应时间及共聚物合成时所用致孔剂对其磺化反应的影响。结果显示,当磺化反应在不同溶胀剂介质中进行时,共聚物的交换容量随交联度变化可呈现不同的关系。与低交联大孔共聚物（交联度７％）比较,高交联大孔共聚物（交联度６０％）磺化反应速度更快,反应能在低得多的温度下进行,同时溶胀介质对磺化产物的交换容量的影响变得很小。６０％交联的共聚     

高交联大孔苯乙烯-二乙烯苯共聚物的微波加热磺化

研究了高交联大孔苯乙烯-二乙烯苯共聚物(60％DVB)在微波加热条件下发生的磺化反应．采用高功率问歇加热的方式，考察了不同的加热方法、溶胀荆、反应物的配比对磺化反应的影响，并与低交联大孔苯乙烯-二乙烯苯共聚物(8％DVB)的磺化反应作了比较．     

高交联大孔苯乙烯/二乙烯苯共聚物的合成及其孔结构的研究Ⅱ

本文对高交联大孔苯乙烯/二乙烯苯共聚物在干态、湿态与溶胀态的孔结构进行了研究。结果表明,在不同的状态中,高交联共聚物的孔结构是不相同的,它们的孔结构会发生变化。但是,它们的孔结构变化远小于低交联共聚物,也就是说,高交联大孔共聚物的孔结构比低交联共聚物的孔结构稳定。 鉴于高交联大孔共聚物的孔结构较稳定,作者把它用作高效液相色谱的进行了初步实验。结果表明,高交联共聚物可做为高效液相色谱的载体固定相。     

采用重复互贯聚合用废弃白球末合成凝胶型阳离子交换树脂的研究

采用重复互贯聚合工艺将废弃白球末加入单体－交联剂－引发剂体系中充分溶胀，再按照常规悬浮聚合和磺化反应工艺合成凝胶型阳离子交换树脂，结果显示，细粒度白球的交联度在4％－7％，单体吸收比为100％，采用盐水滴加工艺保证单体在白球中的均匀扩散和吸收，所合成的阳树脂的各项性能指标均国家标准，这种重复互贯聚合白球与相同交联度的普通白球比较，具有较高的磺化反应活性，较高的交联度，湿真密度，湿视密度和较高的交换容量。     

高交联大孔苯乙烯/二乙烯苯共聚物的合成及其孔结构的研究Ⅰ

利用纯化的二乙烯苯(含量≥95％)作交联剂,合成了一系列苯乙烯/二乙烯苯高交联大孔共聚物,而且较详细地研究了不同聚合条件(如致孔剂用量和组成)对共聚物孔结构的影响。结果表明,高交联共聚物一般都具有高的比表面积,通过调节致孔剂的组成、用量等聚合条件,可以调整和改变共聚物的孔结构。     

高交联苯乙烯-二乙烯苯大孔共聚物的后交联反应

采用工业和实验室合成的高交联大孔苯乙烯－二乙烯苯共聚物,对其对三氯化铁为催化剂,在二氯乙烷溶剂中的后交联反应进行了研究。结果表明,高交联大孔共聚物经后交联反应后,比表面积和孔容都明显增加,增加的幅度与后交联反应条件及大孔共聚物本身的合成条件有重要关系。进一步试验了简化的后交联共聚物的制备方法。所得后交联产物的比表面积仍可达１０００ｍ＾２／ｇ以上,影响后交联反应的因素与未简化的制备方法相同。     

国外离子交换树脂催化剂文摘

本文着重讨论了在过氧化异丙苯的异裂反应中,一系列大网状和大孔磺化苯乙烯—二乙烯苯共聚物离子交换剂平均孔经的增长对于总催化活性的正性影响。对于无孔的磺化阳离子交换剂来说,降低聚合物基体的交联度,可改进初始催化活性。过氧化异丙苯在阳离子交换剂上的异裂反应动力     

大网均孔苯乙烯共聚物的合成、性质和应用(续)

三、大网均孔苯乙烯共聚物的应用1.大网均孔(或称等孔)离子交换树脂的制备大网均孔苯乙烯共聚物很容易进行功能基化反应制备各种基团的离子交换树脂。甚至交联剂含量很高的共聚物,在温和条件下通过磺化反应也可引入磺酸基。M. P. Tsyurupa等采用CMDP、XDC作交联剂制得不同交联度的磺酸阳离子交换树脂,并与DVB交联的树脂作了对比,结果见5~([18])。     

高交换容量苯乙烯大孔强碱Ⅰ型阴离子交换树脂的合成

本工作合成的高交换容量苯乙烯大孔强碱1型阴离子交换树脂80A,理化性能接近于Amberlite IRA900C的水平。80A的重量交换量为4.0～4.4meq/g(干树脂),比表面积为40～50m~2/g,平均孔径为90～100。80A的中间体,是苯乙烯—二乙烯苯共聚物(白球)及其氯甲基化产物(氯球)。白球交联度为6～10,以汽油、液体石腊为混合致孔剂。氯甲基化反应,采用无水三氯化铝为催化剂,反应温度35～40℃,反应时间约8小时,氯球的氯含量高达20～23％。     

大孔共聚物小球的溶胀行为及与固定化酶性能间的关系

本文用溶胀性能自动测定仪测定大孔共聚物小球（以下简称大孔白球）的溶胀性能。并由交联度，致孔剂用量的增加导致大孔白球溶胀性能提高而提出在大孔白球溶胀中存在孔胀大及骨架溶胀胀大二种机理，随孔道结构的改善前者的比例逐增。在孔径适当的前题下，良好的溶胀性参有得固定化酶活性的提高。     

Modification and Application of Poly(Ethylene Terephethalate) Nonwoven Fiber Using Octadecyl Acrylate and Acrylic Acid as Oil Sorbers

Three series of crosslinked octadecyl acrylate and acrylic acid copolymers were prepared through suspension copolymerization based on acrylic acid content (10, 30, 50%wt. ratio). Divinyl benzene (DVB) was used as a crosslinker with different weight ratios (1, 4 and 10%). Isopropyl alcohol or dioctyl phthalate and methyl benzoate were used as two different reaction solvents in the presence of ABIN as initiator. The prepared crosslinked copolymers were characterized by SEM, TGA and FTIR spectroscopic analyses. The prepared polymers were coated onto poly(ethylene terephethalate) nonwoven fiber (NWPET). The effect of copolymerization feed composition, crosslinker wt% and reaction media or solvent on swelling properties of crosslinked polymers were studied through the oil absorption tests in toluene and 10% of diluted crude oil with toluene. It was noticed that the maximum swelling of crosslinked copolymers was increased from 30 to 100 g/g after grafting of copolymers onto NWPET.     

Synthesis and properties of sulfonated and crosslinked poly[(vinylidene fluoride)-graft-styrene] membranes

Crosslinked proton exchange membranes were prepared by electron beam grafting of styrene with divinylbenzene, DVB, or bis(vinyl phenyl)ethane, BVPE, on to poly(vinylidene fluoride), PVDF, followed by sulfonation. The area and thickness increase, crystallinity and mechanical properties of the membranes were investigated. All these properties were influenced by the crosslinker structure and its concentration. The crosslinkers increase the final degree of grafting. For noncrosslinked membranes it was about 80% and with 10% of BVPE crosslinker about 180% after 8 hr. The area increase with grafting is very similar for the noncrosslinked membranes and the differently crosslinked membranes, but the crosslinkers reduce swelling for sulfonated membranes swelled in boiling water. DVB reduces swelling more than BVPE. With grafting, the crystallinity of the PVDF phase decreases; with 10% BVPE the decrease is smallest and with 10% DVB largest. The mechanical properties of the sulfonated swelled membranes decrease with the degree of grafting, for a 10% DVB crosslinked membrane the strength decreases to zero at degrees of grafting higher than 75%. © 1998 John Wiley & Sons, Ltd.     

Thermosensitive superabsorbents based on poly(N,N-diethylacrylamide-co-sodium acrylate)

A series of poly(N,N-diethylacrylamide-co-sodium acrylate) with a degree of crosslinking of 1 mol%have been prepared as thermosensitive superabsorbents for water.The critical swelling temperatures or the volume phase transition temperature(VPTT) and the water absorption capacity of the polymers can be modulated by varying the amount of sodium acrylate(0-60 mol%) in the copolymers.The water absorption and swelling properties of the different hydrogels have been studied as function of temperature.The crosslinked copolymers can absorb large amounts of water at ambient temperatures and dehydrate at higher temperatures with relative ease,making the absorbent materials thermally responsive and thus reusable.The water absorption capacity of the copolymers depends on the pH of the media as the acrylate monomer has a higher water absorption in its deprotonated state.Added urea in the media raises and sharpens the VPTT values of the copolymers containing sodium acrylate.     

高交联苯乙烯—二乙烯苯共聚物的孔结构研究

我们以甲苯或甲苯-正庚烷为致孔剂合成了一系列高交联的大孔苯乙烯-二乙烯苯(St-DVB)共聚物,本文报道这些共聚物的孔结构、孔结构稳定性及其与合成条件的关系。     

Mechanical and morphological studies of sulfonated poly(arylene ether sulfone)s for potential application in fuel cell membrane

Two groups of synthesized sulfonated poly(ether sulfone)s with similar structures but different size of repeat units were selected. Investigation of the properties of these copolymers with different sulfonation contents for application as fuel cell membrane was the main aim of this study. These groups of copolymers showed different thermal behavior, mechanical properties, dimensional and oxidative stability, ion exchange capacity, water uptake, and proton conductivity. Structure–property relation was surveyed, and the copolymers showed acceptable results for use as fuel cell membrane. The swelling ratio of the copolymers was in the range of 3.3–6.6%, and the proton conductivity of them was about 0.020–0.077 S/cm at 25°C. These data were comparable with Nafion 115 with 8.15% of swelling ratio and 0.085 S/cm of proton conductivity. Copyright © 2017 John Wiley & Sons, Ltd.     

四氯化碳存在下大孔苯乙烯-二乙烯苯共聚物的后交联反应

对在四氯化碳存在下 ,大孔St DVB共聚物以三氯化铝为催化剂的后交联反应进行了研究 .结果表明 ,起始共聚物的合成条件 ,包括交联剂DVB的用量 ,致孔剂的性质及其与单体的配比 ,对后交联产物的孔结构有重要影响 .以良溶剂甲苯为致孔剂及采用较高的DVB用量 ,所合成的起始共聚物经后交联后 ,比表面积很容易达到或超过 10 0 0m2 /g .一般情况下 ,后交联产物的孔容增加 ,孔径减小 ,孔结构稳定性明显提高 .当起始共聚物的DVB含量较低时 ,后交联反应以四氯化碳的参与为主 ;当DVB含量较高时 ,后交联反应以起始共聚物中固有的悬挂双键的参与为主     

Swelling Ratios and Rates of Sulfonation of Solvent Modified Copolymers of Styrene Cross-Linked with Pure m-and Pure p-Divinylbenzene

Solvent-modified (toluene) copolymers have been prepared from styrene cross-linked with commercial divinylbenzene, m-divinylbenzene, and p-divinylbenzene at divinyl monomer contents of 16 mole % and 32 mole % at F_M = 0.50. The resultant copolymers have been characterized by swelling-ratio determinations and rates of sulfonation at 60 and 80°C. The solvent-modified 16 mole % cross-linked copolymers sulfonated at rates slightly greater than those characterizing the 8 mole % cross-linked copolymers prepared in the absence of diluent. The order of decreasing sulfonation rates for both the conventional 8 mole % cross-linked systems and for the solvent-modified 16 mole % cross-linked copolymers is commercial divinylbenzene/styrene, p-divinylbenzene/styrene, m-divinylbenzene styrene. The 32 mole % cross-linked systems exhibit a different order of decreasing sulfonation rates: commercial divinylbenzene/styrene, m-divinylbenzene/styrene, p-divinylbenzene/styrene. The swelling ratios of the 32 mole % solvent-modified copolymers were comparable to those of the conventional 8 mole % cross-linked systems.     

UV radiation induced graft copolymerization of allyl acetate onto poly(ethylene terephthalate) (PET) films for fuel cell membranes

Ultraviolet（UV）-induced graft copolymerization of allyl acetate（AA） monomer onto polyethylene terephthalate) （PET） films and the subsequent sulfonation on the monomer units in the grafting chain using chlorosulfonic acid（ClSO₃H） were carried out to prepare proton exchange membranes（PEMs） for fuel cells.A maximum grafting value of 12.8%was found for 35 vol%allyl acetate after 3 h radiation time.Optimum concentration of C1SO₃H was selected for the sulfonation reaction to be 0.05 mol/L based on the degree of sulfonation and the tensile strength studies of the membrane.The degree of sulfonation increased as the sulfonation reaction temperature and sulfonation time were increasing.The radiation grafting and the sulfonation have been confirmed by titrimetric and gravimetric analyses as well as FTIR spectroscopy.The maximum ion exchange capacity（IEC） of 0.04125 mmol g^-1 was found at 12.1%degree of sulfonation and the maximum proton conductivity was found to be 0.035 S cm^-1 at 30℃and a relative humidity of 60%.The various physical and chemical properties of the PEMs such as water uptake,mechanical strength,thermal durability and oxidative stability were also studied.To investigate the suitability of the prepared membrane for fuel cell applications,its properties were compared with those of Nafion 117.     

合成聚乙烯基苯甲酸树脂的研究(Ⅱ)——由氯甲基化交联聚苯乙烯树脂按二步法合成

用两种二步法将交联度6％的大孔氯甲基化聚苯乙烯树脂制成了聚乙烯基苯甲酸树脂,产品氯含量均为零。