SA/PTA/EG共聚酯纤维的性能研究

将丁二酸(SA)部分取代对苯二甲酸(PTA),与玉米基乙二醇(EG)共聚制得SA/PTA/EG共聚酯并对其进行纺丝,研究了共聚酯纤维的可纺性、力学性能和染色性能。结果表明:SA/PTA/EG共聚酯的纺丝温度较常规聚酯的纺丝温度约低25℃。随着SA含量的增加,共聚酯纤维的模量和声速取向度降低,沸水收缩率增加,但SA质量分数(相对于PTA)不宜大于20%。共聚酯纤维染色性能优异,染色温度约90℃,上染率可达90%以上,其耐摩擦牢度和耐洗色牢度均不低于4级。     

PEN合成中NDC与EG酯交换反应工艺及动力学研究

以2,6-萘二甲酸二甲醇酯(NDC)和乙二醇(EG)为原料,以金属盐类为催化剂,在一定条件下,研究了NDC与EG的酯交换反应,探讨了NDC与EG的酯交换反应工艺及动力学规律,不同反应温度下,NDC与EG酯交换反应遵循二级反应动力学规律,反应表观活化能为92.89 kJ/mol。     

生物基EG聚酯的合成及性能研究

利用生物基EG合成聚对苯二甲酸乙二醇酯,并与石油基EG进行了对比。结果表明,生物基EG无DEG、TEG等高沸点微量组分,220 nm紫外透过率略低;用生物基EG合成聚酯时,酯化出水速率和缩聚速率略快;生物基EG合成聚酯的端羧基和熔融结晶温度较低,流变性能与石油基EG合成聚酯相当。     

石墨烯/异山梨醇改性PET聚酯的制备与性能

将石墨烯(Gr)与精对苯二甲酸(PTA)、乙二醇(EG)、异山梨醇(IS)进行共缩聚,制备出了石墨烯/异山梨醇改性PET聚酯(Gr-PEIST),研究了石墨烯对改性PET聚酯的晶型和结构的影响,并对改性PET聚酯的热性能、阻隔性能进行表征。结果表明:石墨烯的加入使改性PET聚酯热稳定性和结晶温度以及结晶速率提高,石墨烯/异山梨醇对改性PET聚酯的玻璃化温度和阻隔性能有所提升。但石墨烯对改性PET聚酯的晶型和结构无影响。     

聚合物前驱体法制备铌酸钾钠纳米粉体

采用聚合物前驱体法,以柠檬酸(CA)为络合剂,乙二醇(EG)为酯化剂合成了纳米级(Na0.35K0.65)NbO3。研究了乙二醇用量对聚合物前驱体稳定性的影响,结果表明n(EG):n(CA)为2时能得到稳定凝胶,与乙二醇和柠檬酸聚酯化反应得到凝胶的理论配比一致。XRD分析表明聚合物前驱体在650℃煅烧2h可制得平均晶粒尺寸为24nm左右,纯单斜相结构的(Na0.35K0.65)NbO3纳米粉体,该合成温度比传统固相法降低了约300℃。     

全球EG市场坚挺新建产能大增

由于亚洲聚酯生产厂家进口势头强劲,全球乙二醇(EG)市场保持健康发展。但是,抗冻剂行业对EG的需求大大低于一年前的需求,以及EG新产能猛增,这将对1998年上半年构成削价的威协。     

聚酯废丝的化学回收研究

使用乙二醇(EG)对有色聚酯(PET)废料解聚,经分离提纯,得到对苯二甲酸二乙二醇酯(BHET)。研究了物料比、反应温度、反应时间、催化剂对醇解率的影响。结果表明,在m(乙二醇)∶m(PET)=2∶1,反应温度196℃,反应时间3 h,催化剂用量为PET质量的0.5%条件下,聚酯解聚很彻底,产物羟值可达434 mg/g以上,主要成分是BHET单体及其低聚物。并通过IR,DSC,HPLC验证了产物的组成,BHET单体纯度可达96.457%。     

Indorama计划在印度尼西亚反向组合进入EG生产

正泰国Indorama Ventures公司(IVL)是聚酯和聚酯原料的主要生产商,该公司于2018年2月23日宣布,计划在印度尼西亚反向组合进入乙二醇(EG)生产。该公司已通知泰国证券交易所,其已在印度尼西亚建立新的子公司PT Indorama Glycol印度尼西亚公司,以进行可行性研究以便在印度尼西亚建立EG装置。     

APP/EG对PIR-PU泡沫材料阻燃性能的影响

以聚磷酸铵/膨胀石墨(APP/EG)为阻燃剂,制备了高阻燃的聚异氰酸酯-聚氨酯(PIR-PU)泡沫材料。采用极限氧指数(LOI)测试、红外光谱分析(IR)、热重分析(TGA)等方法对所制备PIR-PU泡沫材料的燃烧及热降解行为进行了研究。结果表明:APP与EG存在着良好的协同阻燃作用,APP/EG的添加可有效提高PIR-PU泡沫材料的LOI值,其中当APP/EG用量为25份、其配比为3/7时,PIR-PU泡沫材料具有最佳阻燃性能,材料的LOI值可达35.4%。APP与EG的复配使用,使PIR-PU泡沫材料的炭层较单独使用APP或EG时更为致密,有效提高了材料的热分解温度,降低了热降解速率,进而改善了材料的阻燃性能。     

EO/EG装置SHELL和SD技术对比

EO/EG装置因为其良好的经济效益,在液体化工中处于举足轻重的地位。国内EO/EG装置主要采用的是SHELL和SD两家公司的技术。这两家技术各有千秋,互有短长。文章结合国内EO/EG装置生产实际在工艺单元划分、环氧乙烷反应、环氧乙烷吸收、二氧化碳脱除、环氧乙烷精制、环氧乙烷水合反应、多效蒸发及干燥、乙二醇精制、制冷单元等方面对这两家技术进行了对比分析。     

低温合成苯乙烯-马来酸酐交替共聚物

苯乙烯(St)和马来酸酐(MA)自由基引发共聚反应,生成共聚物SMA,是典型的交替共聚。在过氧化苯甲酰(BPO)引发下,以丙酮为溶剂,采用溶液聚合法合成苯乙烯-马来酸酐共聚物,并用收率作为评价标准,对反应条件进行研究。结果表明,在温度为60℃,BPO的质量分数x(BPO)=0.3%,n(苯乙烯)∶n(马来酸酐)=1∶1,w(单体)=30%,反应2 h的条件下,聚合物的收率可达到98.5%。利用化学滴定法测得聚合物中马来酸酐摩尔分数为49.91%,结合理论,证明了合成的苯乙烯-马来酸酐共聚物是一种交替共聚物。一种低温合成苯乙烯-马来酸酐交替共聚物的工艺得到开发。     

Vapor-phase selective hydrogenation of maleic anhydride to succinic anhydride over Ni/TiO2 catalysts

A series of supported Ni/TiO₂ catalysts were prepared by incipient wetness impregnation method under different calcination temperatures, and the as-prepared catalysts were characterized by X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H₂-TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic properties of these Ni/TiO₂ catalysts were investigated in the vapor phase hydrogenation of maleic anhydride (MA) to succinic anhydride (SA). The results showed that the catalytic activity and the selectivity of the Ni/TiO₂ catalysts were strongly affected by the calcination temperature. The catalyst calcined at 1023 K showed a relatively higher SA selectivity of 96% at high MA conversion (96%) under the tested conditions (493 K and 0.2 MPa). The improvement of SA selectivity could be mainly assigned to the presence of suitable metal–support interaction, which can play a role in catalytic property of active nickel species as electron promoter. Besides, the change of surface properties of TiO₂ support with the increasing calcination temperatures, e.g., the decrease of Lewis acid sites, might also have some positive role in reducing the side-products like γ-butyrolacetone (GBL).     

Enhanced dynamic mechanical and shape‐memory properties of a poly(ethylene terephthalate)–poly(ethylene glycol) copolymer crosslinked by maleic anhydride

Dimethyl terephthalate (DMT) and ethylene glycol (EG) were used for the preparation of poly(ethylene terephthalate) (PET), and poly(ethylene glycol) (PEG) was added as a soft segment to prepare a PET–PEG copolymer with a shape‐memory function. MWs of the PEG used were 200, 400, 600, and 1000 g/mol, and various molar ratios of EG and PEG were tried. Their tensile and shape‐memory properties were compared at various points. The glass‐transition and melting temperatures of PET–PEG copolymers decreased with increasing PEG molecular weight and content. A tensile test showed that the most ideal mechanical properties were obtained when the molar ratio of EG and PEG was set to 80:20 with 200 g/mol of PEG. The shape memory of the copolymer with maleic anhydride (MAH) as a crosslinking agent was also tested in terms of shape retention and shape recovery rate. The amount of MAH added was between 0.5 and 2.5 mol % with respect to DMT, and tensile properties and shape retention and recovery rate generally improved with increasing MAH. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 27–37, 2002     

Reactions of low molecular weight highly functionalized maleic anhydride grafted polyethylene with polyetherdiamines

Reaction between low molecular weight highly functionalized maleic anhydride grafted polyethylene and several diamines were carried out using xylene as a reaction media. The influence of varying the amine to maleic anhydride (NH₂/MAH) molar ratio and chain length of diamine on reaction was investigated. It was shown that the reactions of these materials cannot be followed by FTIR measurements alone. In these examples, colorimetric titrations were used to assess residual acid/anhydride content that was not detected by FTIR. The reaction between anhydride and amine was observed to be fast. The degree of reaction and crosslinking in the reactor was observed to depend on the concentration of the reaction mixture and the NH₂/MAH molar ratio. In some cases, a gelatinous insoluble mass was produced in the reactor and this material was not easily processed for further characterization. All soluble reaction products obtained were observed to be thermoplastic and could be melt processed at elevated temperatures. However, further reaction and crosslinking of these materials occurred during processing to produce thermosets, as demonstrated by rheological measurements and sintering experiments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Radical copolymerization of maleic anhydride and substituted styrenes by reversible addition-fragmentation chain transfer (RAFT) polymerization

Reversible addition fragmentation transfer (RAFT) copolymerization with benzyl dithiobenzoate (BDTB) as chain transfer agent was used to copolymerize maleic anhydride (MA) with styrene (St) and with the substituted styrenes p-chlorostyrene (pClSt), p-methoxystyrene (pMeOSt) and p-methylstyrene (pMeSt). Kinetic studies indicated that radical copolymerizations proceeded with apparent ‘living’ character, deduced from experiments demonstrating an increase in molar mass with monomer conversion, narrow molar mass distribution and chain extension to form block copolymer. All copolymers were alternating in chain structure as confirmed by determinations of monomer reactivity ratios. The degree of control in the RAFT mechanism and the establishment of the fragmentation equilibrium incorporating MA are discussed for styrene and for p-substituted styrenes, in relation to experimental copolymerizations producing molar masses somewhat higher than expected. For copolymerizations of MA with α-methylstyrene (αMeSt), conventional rather than controlled behaviour was observed, suggesting that the fragmentation equilibrium could be shifted towards the αMeSt propagating radical.     

Maleic anhydride grafting of polypropylene: peroxide and solvent effects

Abstract

The grafting of polyolefins with maleic anhydride (MA) has been incorporated into industrial practice to generate copolymers that can act as coupling agents between the non-polar polyolefins and different polar fillers and reinforcements. In the present study, two different peroxides were used to initiate the MA grafting onto polypropylene (PP), namely dicumyl peroxide (DCP) and 1,3-bis (terbutylisopropyl peroxi)benzene (DIBP). The use of DIBP allowed similar grafting yields to DCP to be obtained, but with less chain scission of the polyolefin. Moreover, the utilisation of a coagent, toluene (Tol), leads to a reduction in the chain scission of PP. A monotonous decrease in the melt flow index (MFI) of the polymer was observed with increasing molar ratio of Tol/MA, in the range of ratios considered (0–2·5). In addition, the free radical grafting of MA onto PP remained high and optimum grafting was obtained for a molar ratio Tol/MA of ～0·5. It was observed that the addition of toluene was effective, independent of the reaction process utilised, namely batch mixing or extrusion.     

马来酸酐和呋喃的Diels-Alder反应研究

本文详细考察了马来酸酐和呋喃的Diels-Alder反应.得出了最佳反应条件为：反应时间为16h、马来酸酐和呋喃最佳摩尔比5∶1、最合适的溶剂丙酮.产品的转化率达82.5％.用1HNMR进行了表征.     

马来酸酐改性聚醋酸乙烯酯乳液的研究

以马来酸酐(MA)作为醋酸乙烯酯(VAc)的改性共聚单体,采用半连续种子乳液聚合法合成了改性聚醋酸乙烯酯(PVAc)乳液,并考察了MA含量对VAc/MA共聚乳液性能的影响。结果表明:当w(MA)=0.3%～0.4%(相对于VAc质量而言)时,改性乳液的聚合稳定性、储存稳定性和稀释稳定性良好;随着MA含量的不断增加,种子反应阶段回流时间延长,共聚速率变慢,最终合成的改性乳液黏度逐渐增大;当w(MA)=0.4%时,改性乳液的综合性能相对最好,其粘接强度(9.70 MPa)比VAc均聚乳液增加了70%。     

Compatibilization of poly(lactic acid)/epoxidized natural rubber blend with maleic anhydride

The objective of this work was to determine the compatibilization effect of different concentrations of maleic anhydride (MA) in poly(lactic acid) blended with epoxidized natural rubber (PLA/ENR). ENR-grafted MA [ENR-g-MA] was synthesized using four concentrations of MA: 0.15, 0.30, 0.45, and 0.60 phr. Using an internal mixer, binary (PLA/ENR, PLA/ENR-g-MA) and ternary (PLA/ENR/ENR-g-MA) polymer blends were prepared with a constant rubber content of 10 wt %. ENR impaired the mechanical properties of PLA, perhaps due to the relatively large size of the rubber particles. The compatibilization effect of MA was evaluated from the results of impact strength testing. ENR-g-MA was a toughening agent for PLA when the concentration of MA was in the range of 0.30–0.60 phr. MA increased miscibility between PLA and ENR. This effect was indicated in the blends by reductions in rubber particle size, the glass transition temperature of PLA, and the α-transition temperatures of PLA and ENR. In the binary polymer blends, the MA concentration in ENR-g-MA that produced the optimal mechanical properties of PLA was 0.60 phr. In the ternary blends, mechanical properties of PLA did not improve at any concentration of MA in ENR-g-MA. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48297.     

顺酐液相加氢制备丁二酸酐

一步法顺酐加氢生产丁二酸酐的最佳条件为:加氢压力1~1.6 MPa,反应温度50~100℃,反应时间1~2 h,骨架镍催化剂用量是顺酐用量的4%~6%,搅拌速度300 r/m in,在此条件,丁二酸酐的最高收率可达90%以上。