PPG/PTHF对MC尼龙结晶行为的影响

采用DSC、SEM、解偏振光法研究了共聚醚对MC尼龙结晶行为的影响,发现PPG/PTHF-PA共聚物是一个半相容体系,不同分子量的共聚醚与MC尼龙的相容性不同,随着共聚醚分子量、含量的增加,相容性、结晶度呈现先上升而后下降峰形变化,球晶变小,结晶也不完善.共聚醚在MC尼龙结晶过程中起异相成核作用.研究发现,PPG/PTHF部分向尼龙部分渗透,在尼龙保持完整球晶同时,PPG/PTHF能均匀分散在PA基体中,此时共聚物具有优良的力学性能.     

引发剂和活化剂用量对MC尼龙性能的影响

通过改变催化剂(包括引发剂和活化剂)用量合成四个系列MC尼龙,研究了引发剂和活化剂用量的变化对MC尼龙合成、结构和力学性能的影响。实验结果表明：引发剂和活化剂的用量对MC尼龙的对聚合速率、单体转化率、结晶度和结晶温度有一定的影响,同时也对拉伸强度、缺口冲击强度、弯曲强度和弯曲模量影响很大。     

半芳香共聚尼龙6T/6的合成与结晶性能研究

通过溶液共聚的方法制备了半芳香共聚尼龙6T/6,并系统研究了共聚单体配比、共聚反应温度、时间等工艺因素对共聚物熔点、特性黏数和结晶性能的影响规律.     

聚醚型聚氨酯预聚体增韧MC尼龙的研究

将聚醚型预聚体与己内酰胺单体共聚,制备单体浇铸尼龙(MC尼龙)/聚氨酯共聚物。研究了预聚体的异氰酸指数(R=—NCO/—OH)和预聚体质量分数对MC尼龙/聚氨酯共聚物的力学性能、维卡软化温度和结晶度的影响。结果表明:PPG和PTMG预聚体对MC尼龙的增韧效果较好,且PTMG预聚体在R=1.6、质量分数为10%时增韧效果最好,缺口冲击强度达到23.1kJ/m2。随聚氨酯预聚体质量分数的增加,MC尼龙的维卡软化温度逐渐下降,结晶度和熔点均降低。     

共聚尼龙6/66/1212的表观相图研究

采用显微熔点法测定了尼龙6／尼龙66／尼龙1212共聚物的表观相图,显示了共聚尼龙组分配比对其熔点的决定性作用,并给出共聚尼龙6／66／1212熔点与其各尼龙盐组分配比之间的定量关系。     

聚醚型MC尼龙的合成与性能

首先用丙二醇和四氢呋喃共聚醚制备出不同分子量的大分子活化剂然后用它引发己内酰胺聚合，合成出不同软、硬段比例的聚醚型ＭＣ尼龙。研究了大分子活化剂分子量、含量对ＭＣ尼龙的单体转化率、分子量、熔点、力学性能的影响     

MC尼龙/纳米MgO复合材料的制备与性能

采用硫酸铵和碳酸氢铵以及轻烧Mg O粉为原料,利用液相沉淀法制备高纯纳米级Mg O。同时对纳米Mg O进行表面改性,使其可以更好地分散在MC尼龙基体中。将改性后的纳米Mg O,以氢氧化钠为催化剂,甲苯二异氰酸酯为活化剂对MC尼龙进行单体浇铸,制得MC尼龙/Mg O复合材料。结果表明,经纳米Mg O粒子改性后的MC尼龙,其冲击强度和拉伸强度比纯MC尼龙都有所提高,具有增韧和增强的双重效果。     

尼龙6/尼龙共聚物共混体系的热行为研究

探讨了两种尼龙共聚物对尼龙６共混改性物的热行为的影响，表明：含酰胺和酯两种基团的共聚尼龙，因其含酯基而减弱了尼龙６分子链间相互作用的结果，促进了尼龙６的结晶作用，致使冰骤冷试样观察不到冷结晶峰，仅含酰胺基团的共聚尼龙，基本上没改变尼龙６分子间的氢键相互作用，但共聚尼龙的非结晶性和无序的链结构，导致它对尼龙６结晶过程的干扰，表现为熔体结晶峰温降低和冷结晶峰温提高及峰强度（峰高）增大。     

MC尼龙改性研究的新进展

综述近年来铸型（MC）尼龙在减磨、增强、增韧和抗静电四个方面改性研究的新进展。使用固体润滑剂复配及液体润滑剂NZ－HA型矿物油等使MC尼龙耐磨性能有进一步的改进；引入纳米蒙脱土、环烷酸稀土等填充物使MC尼龙强度、尺寸稳定性和耐热性能明显提高；通过嵌段共聚方法获得了冲击性能大幅度提高的MC尼龙嵌段共聚物；将透明的抗静电剂磺酸盐A和辅助抗静电剂HPT配合改善了抗静电剂在MC尼龙中的分散效果。     

超高相对分子质量乙烯/1-十二烯共聚物的合成

选用芴基胺基二甲基钛配合物为主催化剂,在改性烷基铝氧烷(MMAO)和2,6-二异丙基苯酚(BHT)的活化下,进行了乙烯与1-十二烯的共聚。结果表明:芴基上引入叔丁基、胺基上引入金刚烷基的芴基氨基二甲基钛配合物对乙烯/1-十二烯的共聚表现出高活性;共聚活性随着Al与Ti物质的量比的增大逐渐上升,当Al与Ti物质的量比为1000时,达到最高活性,为2600 kg Polymer/(mol Ti·h),所得共聚物的重均分子质量最高达到2.7×10~6g/mol,当1-十二烯添加量为6.8 mmol时,共聚物中1-十二烯的插入率达到0.34%,此时共聚物的熔点为124.6℃。     

Die Polymerisation von Lactamen. IV. Die anionische Copolymerisation von 6-Caprolactam mit 8-Caprylolactam

Conditions were defined for preparing homogeneous castings based on copolymers of 6-caprolactam and 8-caprylolactam under conditions of the low-temperature adiabatic copolymerization of the two lactams below the melting point of polymeric products (catalyst: sodium salt of lactams, activator: N-acetyl-6-caprolactam). The content of 8-caprylolactam in the copolymer cannot exceed 30 mole-% owing to its high polymerization heat and to the dependence of the copolymer melting point on the concentrations of the two lactams; the homopolymerization of the 8-caprylolactam cannot be accomplished under these conditions. The copolymer melting point exhibits a minimum in the region of the equimolar ratio of the two lactams. Further, the temperature dependence of the 8-caprylolactam specific heat was determined over an interval of 100 to 226°C (C_p = 0.2543 + 0.0007 T). The copolymerization rate of the anionic process increases with increasing content of 8-caprylolactarn, in accordance with differences of several orders existing between homopolymerization rates of the two lactams. The content of water extractable portions in the copolymers drops proportionally to increasing content of 8-caprylolactam, similarly as in equilibrium copolymers prepared by the hydrolytic copolymerization.     

苯并口恶嗪/环氧树脂共聚固化过程研究

采用FT-IR、DSC研究苯并口恶嗪与环氧树脂通过熔融搅拌混合均匀后,固化过程中2种树脂发生开环共聚合的可能性。结果表明:苯并口恶嗪与环氧树脂熔融混合后,在高温区(180℃,200℃)发生了共聚反应,苯并口恶嗪开环过程形成的中间体可以作为环氧树脂的固化剂使用。玻璃化转变温度随着共聚体系中环氧树脂含量的增加先升高,环氧树脂质量分数超过30%后降低,当苯并口恶嗪与环氧树脂的质量比为70/30时,Tg达到最高(218℃),熔融共混在一起程度上提高了共聚体的玻璃化转变温度。     

醋酸乙烯共聚物碱醇解研究

本文以氢氧化钠 NaOH 为催化剂,甲醇为溶剂进行醋酸乙烯(VAC)——不饱和二元羧酸共聚物的醇解反应,研究了各种因素对醇解反应速率的影响,得到了宏观动力学规律,为制备共聚改性聚乙烯系列高分子表面活性剂工艺配方的确定,以及醇解度的控制提供了基础数据。     

气相法铬系聚乙烯催化剂QCP-01的评价

从聚合温度、压力对催化剂活性和聚合产物性能的影响,以及催化剂的氢调、共聚性能、聚合动力学等几个方面对负载型含铬催化剂ＱＣＰ０１ 进行了气相法聚合小试评价,结果表明：催化剂活性随着聚合温度、压力、共聚单体（ 一定范围） 的增加而增加,聚合产物熔体指数随聚合温度、压力、氢气、共聚单体的增加而增加。     

氟代丙烯酸酯共聚物的合成及溶液性能

以甲基丙烯酸十二氟庚酯(FA)和甲基丙烯酸(MAA)为单体,偶氮二异丁腈(AIBN)为引发剂,二氧六环为反应介质,制备了氟代丙烯酸酯共聚物。聚合条件为:聚合温度75℃,单体量比n(FA)∶n(MAA)=(1∶9)~(4∶6),单体的质量分数w(FA+MAA)=25%,引发剂AIBN为单体总质量的1.5%。用红外光谱、核磁共振氢谱、元素分析、示差扫描量热分析、热重分析和凝胶渗透色谱对产物结构进行了确认和表征。研究了共聚物溶液的性质。结果表明:该聚合物具有聚电解质的黏度行为,在纯水中其比浓黏度随溶液质量浓度的降低而增加;在纯水中聚合物具有表面活性,其表面活性随着聚合物结构中氟碳链质量分数的增加而提高,该聚合物可以用作制革生产中的防水复鞣剂。     

Synthesis,characterization of star-shaped copolymers of <Emphasis Type="SmallCaps">l</Emphasis>-lactide and epoxidized soybean oil

Biodegradable star-shaped PLLA–ESO copolymers were synthesized by the bulk copolymerization of l-lactide (l-LA) and epoxidized soybean oil (ESO) with stannous octanoate as the catalyst. Effects of molar ratios of monomer to catalyst, and various amounts of ESO on copolymerization were studied. The resulting copolymers were characterized by FTIR, ¹H NMR, GPC, etc., which confirmed the successful synthesis of star-shaped copolymers of l-LA and ESO. The thermal and mechanical properties of samples were also investigated by means of DSC, TGA and tensile testing. The results showed that the PLLA–ESO copolymers possed lower glass transition temperature, melting point, crystallinity, and maximum decomposition temperature than those of neat polylactide. Tensile testing demonstrated that PLLA–ESO copolymer had better ductility than linear PLLA. It was also found that the amount of catalyst almost had no influence on the weight average molecular weight of PLLA–ESO copolymers, but which could be controlled by variation of molar ratios of l-LA to ESO.     

Studies on the synthesis and thermal properties of copoly(L‐lactic acid/glycolic acid) by direct melt polycondensation

A two‐step direct copolymerization process of L ‐lactic acid (L ‐LA)/glycolic acid (GA) was developed. The first step was to produce an oligomer of L ‐LA/GA and then the oligomer was polymerized with binary catalyst tin chloride dihydrate/p‐toluenesulfonic acid. In this way, the copoly(L ‐LA/GA) (PLGA), without any organic solvent, was synthesized directly. The thermal properties and solubility in chloroform of PLGA were studied by DSC and NMR. The results showed that the melting point of PLGA decreases with increasing mole fraction of GA units in copolymer. In addition, the melting point of polymer also decreased with increasing degree of racemization of polymer. The solubility of PLGA in chloroform decreased with the increase of the average lengths of the glycolic acid units. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2163–2168, 2004     

Synthesis and Characterization of Poly(glycidyl nitrate‐block‐caprolactone‐block‐glycidyl nitrate) (PGN‐PCL‐PGN) Tri‐Block Copolymer as a Novel Energetic Binder

An energetic binder was synthesized through ring opening copolymerization of glycidyl nitrate (GLYN) with polycaprolactone (PCL) as a macroinitiator to form tri‐block copolymer PGN‐PCL‐PGN. Effect of monomer concentration, catalyst, reaction time and solvent was investigated in polymerization. Resulting tri‐block copolymer was characterized by Fourier transform infrared spectroscopy (FT‐IR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The DSC result shows that glass transition temperature of tri‐block copolymer (T_g=−56.2 °C) is lower than PGN (T_g=−35 °C). In optimal condition, the M_w of this polymer was obtained 2900 g/mol.     

纳米材料催化马来酰亚胺共聚反应

研究了用复合纳米ＴｉＯ２催化的马来酰亚胺的共聚反应。经差热分析、预聚体的溶解性及凝胶特性测试结果表明：引入单马来酰亚胺与双马来酰亚胺进行共聚,可降低共混和的熔点及提高预聚体的溶解性;使用复合纳米ＴｉＯ２作催化剂,能显著降低共聚树脂的固化温度。上述改进将明显改善以马来酰亚胺树脂为基体的复合材料的加工性能。     

Microstructure of Ethylene/Propylene Random Copolymers Prepared by a Fluorinated Bis(phenoxy-imine)Ti Catalyst

Summary Living copolymerization of ethylene and propylene was catalyzed by a fluorine-containing bis(phenoxy-imine) titanium catalyst. A series of ethylene-propylene copolymers with different propylene contents were prepared and the copolymers were characterized by ¹³C-NMR, GPC and DSC. The copolymers were found to have the following characteristics: (1) Molecular weight distribution of the copolymer is rather narrow; (2) There exist only isolated propylene units distributed along the polymer chains even at propylene content as high as 14.9 mol%; (3) The distribution of ethylene sequence are not homogeneous. Insertion of propylene changes from 2,1-insertion in homopolymerization into 1,2-insertion when the preceding unit is ethylene.