PP／EPDM／HDPE三元共混增韧及增韧机理分析

对ＰＰ／ＥＰＤＭ／ＨＤＰＥ三元共混增韧进行了有效的研究、发现ＥＰＤＭ和ＨＤＰＥ在ＰＰ基体中起到了协同增韧作用这种协同增韧 基于形成了特定的ＥＰＤＭ－ＨＤＰＥ壳核结构，使材料韧性和强度兼优。     

反相悬浮法合成AA/AM/AMPS耐盐高吸水性树脂

为了提高高吸水性树脂的吸液性能,实验采用反相悬浮聚合法,向丙烯酸(AA)/丙烯酰胺(AM)二元体系中引入2-丙烯酰胺基-2-甲基丙磺酸(AMPS)作为第三种聚合单体合成高吸水性树脂.通过正交试验研究单体配比、丙烯酸中和度、交联剂用量和引发剂用量四个因素对产品性能的影响.红外光谱和扫描电镜测试结果显示产物为AA/AM/AMPS三元共聚物,粒子呈球形,球表面为褶皱状.最佳实验条件:单体摩尔配比(AA/AM/AMPS)为1.25∶1∶0.7,丙烯酸中和度为90%,交联剂用量(占单体总量)为0.08%,引发剂用量为0.7%.此条件下产品的吸蒸馏水率可达1 720 mL/g,吸盐水率达165 mL/g.     

PP／EPDM共混物的力学性能及形貌研究

对PP／EPDM共混物的力学性能进行了研究,并用扫描电子显微镜（SEM）观察了共混物的形貌特征。结果表明,随EPDM含量增加,拉伸强度、拉伸弹性模量、弯曲强度、弯曲弹性模量均下降,但冲击强度在EPDM含量约为30％时出现极大值。除了分散相球粒的粒径和粒间距外,分散相在基体中的形状对共混物的冲击强度也有很大影响。同时,SEM结果表明,EPDM参与了PP的结晶过程。     

甲基丙烯酸十八酯基油溶性聚合物反应过程的在线红外研究

采用React IRTM4000在线红外检测装置和Auto-RC(reaction calorinleter)等温反应量热器对以甲基丙烯酸十八酯、马来酸酐、苯乙烯为原料的三元共聚过程进行了反应动力学研究和热量变化研究.研究结果表明,酯基、酸酐、苯环的吸光度随时间变化基本保持不变;C=C键断裂过程中吸光度随时间的变化情况...     

Properties of Paper Sludge Filled Polypropylene (PP)/Ethylene Propylene Diene Terpolymer (EPDM) Composites: The Effect of Silane-Based Coupling Agent

Paper sludge was used as a filler in PP/EPDM composites and 3-aminopropyl triethoxysilane (3-APE) was used in this study as a coupling agent. The effects of filler loading and 3-APE on the mechanical properties, water absorption, morphology, and thermal properties of the composites were investigated. It was found that incorporation of a silane coupling agent (3-APE) increased the stabilization (equilibrium) torque, tensile strength, and Young's modulus but decreased the elongation at break and water absorption. Scanning electron microscopy (SEM) study of the tensile fracture surface of the composites indicated that the presence of 3-APE increased the interfacial interaction between paper sludge and PP/EPDM matrix. The addition of a silane coupling agent also increased the crystallinity of PP and thermal stability of PP/EPDM/PS composites.     

Conifer fibers as reinforcing materials for polypropylene‐based composites

Conifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in improved processing, as well as improvements in the thermal and mechanical properties of the resultant composites compared with the composites filled with untreated conifer fibers. Moreover, MAPP grafting and MAPP treating displayed more obvious benefits than EPDM treating in terms of thermal properties, processing flowability, and tensile strength improvements. EPDM treating also produced more significant benefits than either MAPP grafting or MAPP treating in terms of impact strength and tensile elongation improvements. These improvements were attributed to surface coating of the fibers when EPDM was used. In addition, the effect of the concentration of the conifer fibers on the properties of the composites and the difference between MAPP grafting and MAPP treating were evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2833–2841, 2001     

HPM/St/MA三元共聚物的合成及其热分解动力学

采用溶液聚合法制备了N-(4-羟基苯基)马来酰亚胺/苯乙烯/马来酸酐三元共聚物,通过红外光谱对其结构进行了表征,并利用TG和DTG技术对该共聚物的热性能和热分解动力学进行了研究。结果表明,由Fly-nn-Wall-Ozawa法求得三元共聚物的热分解表观活化能为147.38 kJ,指前因子为2.62×1010;Crane法求得的反应级数为0.95。该共聚物热分解受单机理控制,初始热分解温度为660 K,最大热分解温度为707 K,在740 K时热分解基本结束,较二元共聚物St/MA其耐热性明显提高。     

Mixing efficiency in co‐rotating batch mixer for preparation of NR/EPDM blends

An in‐house developed co‐rotating batch mixer was used to prepare the blends of natural rubber (NR) and ethylene‐propylene‐diene terpolymer (EPDM) in the present work. Phase morphology and magnitude of dispersive mixing efficiency offered by the in‐house developed co‐rotating batch mixer and a conventional counter‐rotating batch mixer were compared. It has been found that the co‐rotating batch mixer equipped with the MX2 rotor configuration could improve the dispersive mixing efficiency of NR/EPDM blends considerably. A poor state‐of‐mix in blends, particularly at high fill factor, could be overcome by the utilization of MX2 rotor configuration where the extensional flow is probably facilitated in the converging zones. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Morphology,rheology, and mechanical properties of dynamically cured EPDM/PP blend: Effect of curing agent dose variation

The structure development, rheological behavior, viscoelastic, and mechanical properties of dynamically cured blend based on the ethylene–propylene–diene terpolymer (EPDM) and polypropylene (PP) with a ratio of 60/40 by weight were studied. The variation of two‐phase morphology was observed and compared as the level of curing agent was increased. Meanwhile, as the level of curing agent increased, viscosity as a function of shear stress always increased at a shear stress range of 2.2 × 10⁴ to 3.4 × 10⁵ Pa at the temperature of 200°C, yet viscosity of the blend approached each other at high shear stress. Dynamic mechanical spectra at different temperatures show that dynamic modulus (E′) of the blend exhibits two drastic transitions corresponding to glass transition temperature (T_g) of EPDM and T_g of PP, respectively. In the blends T_gs of EPDM increase and T_gs of PP almost remain unchangeable with an increase in curing agent level. Tensile strength increased, yet elongation at break decreased as the level of curing agent is increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 357–362, 2004     

Co‐delivery of methotrexate and doxorubicin via nanocarriers of star‐like poly(DMAEMA‐block‐HEMA‐block‐AAc) terpolymers

Combined therapy is a promising strategy for clinical cancer treatment with synergistic effects. The purpose of the work reported was to evaluate a smart nanocarrier for co‐delivery of doxorubicin (DOX) and methotrexate (MTX). Since star‐like nanocarriers can load a high dose of drugs with various properties, we developed star polymer nanomicelles based on poly[(2,2‐dimethylaminoethyl methacrylate)‐block‐(2‐hydroxyethyl methacrylate)‐block‐(acrylic acid)] having potential for multi‐drug delivery. The nanomicelles demonstrated high encapsulation efficiency, i.e. 97.1% for DOX and 79.5% for MTX. To this end, the star‐like terpolymers were synthesized via atom transfer radical polymerization with pentaerythritol as an initiator. The micellar properties and dual stimuli‐responsive behaviour of the terpolymers were investigated using transmission electron microscopy, field emission scanning electron microscopy and dynamic light scattering measurements, concluding that this co‐therapy offers a promising approach for cancer treatment. © 2019 Society of Chemical Industry