Surface Modification of Nanoclays with Styrene-Maleic Anhydride Copolymers

This study presents the modification of surfaces of nanoclays, halloysite nanotubes (HNT) and sepiolite (SEP), with styrene-maleic anhydride copolymers (SMA) via esterification reaction between hydroxyl groups of the nanoclays and anhydride groups of SMA. The structural, thermal, and morphological analyses of the modified nanoclays were performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). All of these results suggested that the expected modification of HNT and SEP surfaces were performed. Although XRD patterns of HNT containing samples showed that the basal spacing shifted to higher distances, it was found that those of the crystalline structure of SEP remained unchanged. Thermal gravimetric analysis exhibited that SMA copolymers were grafted onto the surfaces of nanoclays varying amounts between 15 and 43 wt. % depending on the types of nanoclays and SMA copolymers. This modification indicates that these nanoclays can be added to the polystyrene matrix without any compatibilizers.

Influences of Reactive Compatibilizer R-Styrene-Maleic Anhydride Copolymer on PA6/PP Blends

The effect of R-styrene-maleic anhydride copolymer （R- SMA） compatibilzation on Nylon 6 （ PA6 ）/polypropylene （ PP ） blends has been investigated experimentally through Molan test, microscopic morphology, and chemical structure. Results show that the moderate R-SMA addition can promote reaction between anhydride in R-SMA and amino in PA6, and lead to a new PA6-g- R-SMA copolymer in the blends. Such PA6-g-R-SMA eopolymer in the blends can effectively reduce the interfaeial tension and PP particle size, and improve the compatibility of two immiscible phases in the blends. The crystallinity of PA6 in PA6/PP blends has greatly decreased by PP blends. The blends have the best comprehensive mechanical and thermal properties when the mass ratio of PA6/PP/ R-SMA is 90：10：2 to 90：10：4. The impact strength of the PA6/PP blends with the eompatibilizer is increased by more than 150 %.

CONTROLLED RADICAL COPOLYMERIZATION OF STYRENE AND MALEIC ANHYDRIDE UNDER GAMMA RADIATION IN THE PRESENCE OF BENZYL DITHIOBENZOATE

The copolymerization of styrene (St) with maleic anhydride (MAh) under gamma radiation at room temperature in the presence of benzyl dithiobenzoate (BDTB) was found to display 'living' nature evidenced by constant concentration of chain radicals during the copolymerization, linear evolution of molecular weights with conversion and narrow molecular weight distribution (M-w/M-n = 1.23-1.35). The compositional analysis and the sequence structural information of the copolymers obtained from DEPT (Distortionless Enhancement by Polarization Transfer) experiments demonstrate that the copolymers obtained also possess strictly alternating structure.

Kinetic Study of Carbonylation of Methyl Acetate to Acetic Anhydride Catalyzed by Rhodium Complex with a Ligand of Copolymer of Vinyl-acetic Ester and Acrylonitrile

The copolymer of vinyl acetic ester and acrylonitrile is used to react with [Rh（CO）2Cl]2to form a complex which can be used in the carbonylation of methyl acetate to acetic anhydride. Many factors affecting the reaction rate, catalytic activity and selectivity have been investigated. The reaction rate depends on rhodium complex and methyl iodide, and is differant from that of homogenous small molecular rhodium complex catalyst. It is revealed thatthe reaction rate is zero order in CO, first order in Rh and LiOAc, but the order in CH3I is complicated. The causes of these phenomena are discussed based on the mechanism of carbonylation of methyl acetate.

A NOVEL COPOLYMER-BOUND CIS-DICARBONYLRHODIUM COMPLEX FOR THE CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE

A series of porous microspheres of linear and ethylene diacrylate (M') cross-linked copolymers of 2-vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol-acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.

POLYMERIC IONIC CONDUCTORS MODIFIED WITH POLAR GROUPS: PART Ⅱ. STRUCTURE-IONIC CONDUCTION RELATION IN LI-COMPLEX BASED ON MALEIC ANHYDRID E-COPOLYMERIZED METHACRYLATES

Ringlike polar monomer maleic, anhydride (MAn) was copolymerized with oligo (oxyethylene) methacrylate (MEO_n), and its effect on ion conduction property of the corresponding polymer-salt complexes was studied. As a consequence the introduction of MAn onto polymer chain retards crystallization of the ether pendants considerably, and improves the ion conductivity to a larger degree compared with other polar groups once investigated (σ_(max),25℃=8.5×10^(-5) S/cm). The structure-ion conduction relation in the polymer-salt matrix is also analyzed macroscopically through the correspondence between composition-dependences of polymerization conversion and isothermal ion conductivity, and microscopically through the measurements of cross polarized light and electron transmission.

SYNTHESIS AND THERMAL PROPERTIES OF A NEW CHOLIC ACIDCONTAINING COPOLYMER

A new copolymer was synthesized by free radical polymerization in solution from methyl 3α-methylacryloyl-7α, 12α-dihydroxy-5β-cholan-24-oate (MACAME) and maleic anhydride (MAN). The copolymer was characterized by FT-IR and functional group analysis. The reactivity ratios of the two monomers were estimated [r_1 = 11.6 (MACAME), r_2 = 0.01(MAN)] by conducting a series of copolymerizations with a variety of monomer feed compositions and analyzing thecopolymer composition. Thermogravimetric and differential scanning calorimetric analyses of the samples indicate that thecopolymer possesses good thermal stability. The temperature at which the copolymer samples experienced a 10% weight loss(T_(WL)) is over 287℃, and the T_g ranged from 174 to 185℃ for the copolymers.

Potassium Acetate/18-Crown-6 Pair:Robust and Versatile Catalyst for Synthesis of Polyols from Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides

Efficient synthesis of polyester polyols with tunable molecular weight and microstructures from cyclic anhydride/epoxide mixtures by taking advantage of chain transfer reaction remains a great challenge,because most of the catalysts exhibit poor tolerance to chain transfer agent(CTA).In this contribution,we demonstrated that potassium acetate(KOAc)and 18-crown-6(18-C-6)combination has great potential in the synthesis of diverse polyester polyols with controllable molecular weight and high-end group fidelity.Com-pared with KOAc,KOAc/18-C-6 pair could induce a much faster chain transfer between the active and dormant chains,and thus produce polyester polyols with narrow and monomodal distribution.In addition,polyester polyols could be efficiently prepared in laboratory by using commercially available cyclic anhydride without further purification(containing about 2%diacid residual as CTA)with an extremely low catalyst loading([catalyst pair]:[anhydride]:[epoxide]=1:50000:250000,[catalyst pair]=0.0004 mol%).KOAc/18-C-6 could also promote the self-switchable copolymerization of cyclic anhydride/epoxide/cyclic ester mixtures.Ring-opening copolymerization of cyclic ester was initiated automatically after the full conversion of cyclic anhydride,finally producing polyester polyols with ABA-type block structure.

接枝共聚物对乙烯-乙烯醇共聚物/聚乙烯共混物结构及性能的影响

通过熔融共混法制备了乙烯-乙烯醇共聚物(EVOH)/低密度聚乙烯(LDPE)共混物,再加入马来酸酐接枝聚乙烯(PE-g-MAH)用于促进EVOH的分散性。利用DSC、SEM、力学性能测试、阻隔性能测试等方法表征了共混物的结构及PE-g-MAH的加入对共混物性能的影响。实验结果表明,LDPE与EVOH不相容,EVOH以球形颗粒均匀分散在LDPE基体中,添加PE-g-MAH后可显著改善EVOH的分散性,大幅降低EVOH的结晶温度,进一步提高EVOH/LDPE共混物的强度及对一类萜类物质的阻隔性能。另外,当EVOH含量为10%(w)时,EVOH/LDPE共混物的阻隔性能相对纯LDPE有明显提升,之后进一步提高EVOH含量,阻隔性能变化不大。

羧基功能化交联共聚物微球的制备及其对亚甲基蓝的吸附性能

以二乙烯苯(DVB)为交联剂,α-甲基苯乙烯(AMS)、马来酸酐(MAH)为单体,通过自稳定沉淀聚合原位制备α-甲基苯乙烯-马来酸酐交联共聚物微球(PAMSM),PAMSM与氢氧化钠反应后,转化为羧基功能化的交联共聚物微球(PAMSM-COOH)。对微球的结构进行了表征,研究了PAMSM-COOH微球对亚甲基蓝(MB)的吸附性能以及吸附剂循环利用效果。扫描式电子显微镜(SEM)分析表明,微球表面光滑,具有良好的球形度并且粒径均一。在MB初始质量浓度为200 mg/L,吸附剂用量为0.50 g/L,溶液pH值为7,吸附温度为313 K,吸附时间为4 h,PAMSM-COOH对MB的最大吸附容量为261 mg/g。微球吸附MB的动力学和等温数据分别符合拟二阶模型和Langmuir等温模型,微球吸附MB为自发进行的吸热过程。5次吸附-脱附循环实验表明微球对MB的去除率保持在85.0%以上。

马来酸酐离聚物对聚对苯二甲酸乙二醇酯荧光及非等温结晶动力学行为的影响

以马来酸酐-苯乙烯交替共聚物为原料,采用一步法制备了马来酸酐离聚物并将其用于改性聚对苯二甲酸乙二醇酯(PET),利用荧光光谱法、FTIR、DSC等方法研究了它的荧光性能及对PET荧光、非等温结晶性能及动力学的影响。实验结果表明,马来酸酐离聚物具有荧光性能,将其加入PET后,PET改性物的荧光强度增加、结晶温度升高。Jeziorny法和Mo法计算结果表明,加入马来酸酐离聚物后,PET改性物的结晶速率、晶体生长维数增加,且马来酸酐离聚物添加量越高,PET改性物的结晶改善效果越好,马来酸酐离聚物可增加PET的非等温结晶活化能。

PE/SEBS-g-MAH/SEBS的制备及防污性能

以聚乙烯(PE)网衣为基材,苯乙烯-乙烯/丁烯-苯乙烯嵌段共聚物接枝马来酸酐(SEBS-g-MAH)和苯乙烯-乙烯/丁烯-苯乙烯嵌段聚合物(SEBS)为原料,通过浸涂法制备得到PE/SEBS-g-MAH/SEBS(PSMS);分析讨论了不同SEBS附着率时PSMS的力学性能、表面形貌、表面性质、抗蛋白吸附和抗大肠杆菌吸附等性能。结果表明,PSMS表面呈大小不一的泡孔形貌,且随着SEBS附着率的增大,PSMS表面泡孔密度增大,拉伸强度先增加后降低。当SEBS附着率为46.1%时,PSMS的拉伸强度和表面自由能分别为6.045 MPa和14.055 mN/m,抗蛋白吸附率达93.21%,同时兼具良好的抗大肠杆菌吸附性能。除此之外,PSMS在海洋挂板实验中也表现出良好的防污性能。

SMA含量对PMMA/ASA/SMA三元合金材料性能的影响

为了提升聚甲基丙烯酸甲酯(PMMA)的综合性能并拓宽其在抗冲击和高温环境下的应用范围,采用苯乙烯-马来酸酐共聚物(SMA)和丙烯腈-苯乙烯-丙烯酸酯三元共聚物(ASA)作为改性剂,通过熔融共混技术,制备了PMMA/ASA/SMA三元合金材料。在SMA和ASA总质量分数固定为30%的情况下,研究了SMA含量变化对合金材料力学性能、耐热性能以及组分相容性的影响。结果表明,添加SMA和ASA可显著提升PMMA的断裂伸长率和缺口冲击强度,随着SMA含量的增加,合金材料的拉伸强度和弯曲强度逐渐提升,断裂伸长率先升高后降低,当SMA质量分数为5%时达到最高,较未添加SMA的材料提高32.1%,缺口冲击强度下降,但仍远高于纯PMMA。此外,合金材料的热变形温度与SMA含量成正相关关系,每增加质量分数1%的SMA,热变形温度约提高0.36℃,在SMA质量分数为20%时,热变形温度可提升至103.9℃。SMA的加入有效提高了合金材料的玻璃化转变温度(Tg),与未添加SMA的材料相比,添加质量分数20%SMA的合金材料的Tg从122.50℃提升至133.01℃,增幅达10.51℃。此外,合金材料的损耗因子呈现出单一峰值,表明PMMA/ASA/SMA体系具有良好的相容性。

溶液法接枝改性乙烯-丁烯共聚物工艺研究

溶液法接枝改性聚烯烃,具有接枝均匀、单体残留少等优点,在一些高端应用领域具有优势。采用马来酸酐为接枝单体,考察了单体用量、反应时间、反应温度、溶剂用量、催化剂用量等条件对接枝率的影响。结果表明,反应温度125℃,反应时间2 h,环己酮质量为300%乙烯-丁烯共聚物质量,马来酸酐用量为乙烯-丁烯共聚物质量的25%,BPO用量为乙烯-丁烯共聚物质量的4%时,接枝率可达1.02%。

PRELIMINARY STUDY OF EXTRACTABLE PROTEIN BINDING USING MALEIC ANHYDRIDE COPOLYMER

A preliminary study of using maleic anhydride copolymer for protein binding has been carried out. The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back formation of the anhydride groups. The properties of the film surface were analyzed by attenuated total reflection Fourier transforms infrared spectroscopy and water contact angle measurements. The protein content was determined by Bradford assay. To obtain optimum conditions, immersion time for protein binding was examined. Results revealed that proteins can be successfully immobilized onto the film surface via covalent linkage. The efficiency of the covalent binding of the extractable protein to maleic anhydride-polyethylene film was estimated at 69.87 ug/cm2, although the film had low anhydride content （3%） on the surface.

Homopolymerization and Copolymerization of Adipic Anhydride with ε-Caprolactone Catalyzed by Rare Earth Trisphenolate

The ring-opening polymerization of adipic anhydride and the ring-opening copolymerization of adipic anhydride with ε-caprolactone catalyzed by single component rare earth trisphenolate have been reported. The structure of the copolymer poly（CL-b-AA） has been characterized by SEC, ^1H NMR and DSC.

Exploiting styrene-maleic acid copolymer grafting chromatographic stationary phase materials for separation of membrane lipids

High performance liquid chromatography-mass spectrometry is one of the most commonly used strategies for lipid analysis.The development of versatile chromatographic stationary phases to meet the increasing demands for separation of complex lipids is very important.Styrene-maleic acid(SMA)copolymer is an amphiphilic polymer,which has been proven to have the ability to solubilize lipid molecules of various structures.In this study,styrene-maleic anhydride copolymer coated silica was first prepared by the thiol-ene click reaction.With L-cysteine hydrochloride or dodecanol as the post-modification reagents,Sil-SMA-amino acid and Sil-SMA-dodecanol stationary phase materials were further successfully fabricated via nucleophilic ring-opening reaction.The Fourier-transform infrared,thermogravimetric analysis,and elemental analysis results confirmed the two stationary phase materials were successfully prepared.Furthermore,both the Sil-SMA-dodecanol column and the Sil-SMA-amino acid column possessed reversed-phase/hydrophilic interaction/ion exchange mixed-mode retention mechanisms.The column efficiency of the Sil-SMA-derivatives columns reached 77,300 N/m.Based on the mixed-mode retention characteristics,the Sil-SMA-derivatives columns achieved both the lipid classes and species separation via a single column.The Sil-SMA-amino acid column was further successfully used to separate lipid extract from gastric cancer cell membrane.All these results demonstrated that the SMA-based stationary phase materials have a good potential for use in lipid separation.

马来酸酐共聚物微球对聚丙烯光扩散性能的影响

利用自稳定沉淀聚合技术制备的马来酸酐共聚物微球作为光扩散剂,通过熔融共混的方法制备了光扩散聚丙烯。筛选了聚丙烯基体,研究了共聚物微球对聚丙烯流变性能、光扩散性能和力学性能的影响。研究结果表明,马来酸酐共聚物微球作为光扩散剂可以提高聚丙烯的光扩散性能,共聚物微球添加量为2%时可制备得到雾度大于95%且透光率大于70%的光扩散聚丙烯产品,同时其拉伸强度和弯曲模量达到34 MPa和1.6 GPa,可应用于照明领域。

单分散马来酸酐/己烯交联共聚物微球的制备

采用沉淀聚合法制备了马来酸酐/己烯交联共聚物微球,利用FTIR,TG,SEM等方法研究了微球的化学组成、形貌、粒径和性能,以及聚合条件对微球形貌、粒径及粒径分布的影响。实验结果表明,聚合产率随反应时间的延长、原料浓度和交联剂用量的增加而增加,随聚合温度的升高呈先增加后减少的趋势;共聚物微球形貌受温度影响较小,主要取决于反应时间、原料浓度及交联剂用量等因素;通过调控反应条件可以得到粒径约1μm、粒径分散指数小于1.01的单分散马来酸酐/己烯交联共聚物微球。

PE-g-MAH粘接剂的制备及其在阻隔膜中的粘接性能研究

采用双螺杆熔融挤出法制备了马来酸酐接枝聚乙烯(PE-g-MAH)。探讨了在以基体树脂为线型低密度聚乙烯(LLDPE)的基础上,添加不同种类引发剂含量、不同接枝单体马来酸酐(MAH)含量对制备出PE-g-MAH的性能的影响。同时也探究了不同接枝率、熔融指数以及晶点个数的PE-g-MAH粘接剂在乙烯-乙烯醇共聚物(EVOH)阻隔膜上粘接性能的影响。通过傅里叶变换红外光谱对接枝产物进行定性表征并分析接枝物接枝率,通过熔体流动速率测试分析其流动性,通过180°剥离强度测试分析粘接剂的性能。研究结果表明:当引发剂为过氧化二异丙苯(DCP)且添加0.05份,MAH添加1份时,PE-g-MAH接枝率为0.68%,熔融指数为0.94 g·(10 min)^(-1),晶点个数为12,此时材料粘接性能最佳;选择EVOH作为阻隔层粘接,当接枝率为0.68%时,PE-g-MAH的剥离强度达到最大值为69.0 N/cm,PE-g-MAH粘接剂的粘接性能达到相对最佳。