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...     

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。     

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。     

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     

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     

Starch-AA-CS三元共聚物对酸溶液中碳钢的缓蚀作用

以淀粉（Starch）、丙烯酸（AA）和壳聚糖（CS）为原料合成三元共聚物（SAAC）。利用红外光谱（FT-IR）和X射线衍射（XRD）进行结构表征,并通过电化学方法、失量法、扫描电子显微镜（SEM）和能谱仪（EDS）研究SAAC在1 mol·L^-1 HCl环境下对Q235碳钢的缓蚀作用及机理。结果显示,SAAC是一种混合型缓蚀剂,30℃时,200 mg·L^-1的SAAC的缓蚀率可达90.1%。通过Gibbs自由能和Tafel曲线可知,SAAC在Q235碳钢表面的吸附符合Langmuir吸附等温式,同时存在物理吸附与化学吸附。SAAC合成原料经济、环保,合成条件温和,是一种具有广泛应用前景的绿色环保型缓蚀剂。     

阳离子聚丙烯酸酯无皂乳液表面施胶剂的制备及应用

为制备一种能够明显提高纸张施胶效果和印刷性能的聚合物表面施胶剂,以聚乙烯醇(PVA)为分散剂,乙二醇单丁醚(EGME)为助溶剂,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,通过无皂乳液共聚制备了阳离子丙烯酸酯三元共聚物表面施胶剂。确定了较佳的合成条件:种子聚合法,反应温度85℃,反应时间5·0h,w(DMC)=15%,w(PVA)=4·0%,w(KSP)=0·2%,w(EGME)=1·0%,n(BA)∶n(St)=1·2∶1·0。DSC测量出玻璃化温度为24·8℃;GPC分析出共聚物的数均相对分子质量Mn=85100,MWD=3·94;TEM显示出乳胶粒呈椭球状,其粒径约85nm。以w〔P(St-BA-DMC)〕=2·0%的聚合物乳液进行表面施胶时,可使施胶度达到9s以上,油墨吸收率为26%~27%,拉毛速率为2·9m/s,耐破度为120kPa。实验证明,所制备的三元共聚物无皂乳液表面施胶剂对提高纸张的施胶效果和印刷性能具有明显的作用。     

BA—MMA—GMTS三元共聚大分子表面处理剂的合成及其对高岭土／PVC复合电缆料的改性

采用溶液聚合法合成了BA-MMA-GMTS三元共聚物大分子表面处理剂，应用该大分子表面处理剂对纳米级煅烧高岭土进行表面处理，FTIR表明共聚物包覆了高岭土，TEM观察到处理后高岭土在有机溶剂中的分散良好。DMTA测试显示，用其处理的纳米级高岭土填充制备PVC电缆料的取和Tg转变温区明显降低和拓宽。SEM对该PVC电缆料低温冲击断裂面的观察显示是韧性断裂。检测结果表明用大分子表面处理剂包覆的纳米级煅烧高岭土填充制备的PVC电缆料低温冲击韧性、力学性能和电举性能均最佳。     

反应性弹性体三元共聚物改性沥青及其混合料性能与机制

采用黏度试验和动态剪切流变试验研究了反应性弹性体三元共聚物（RET）对基质沥青与苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）改性沥青性能的影响,通过原子力显微镜（AFM）分析了SBS改性沥青和RET-SBS改性沥青的表面形貌特征,并采用车辙试验、低温弯曲试验、弯曲疲劳试验及加速加载试验评价了RET改性沥青混合料的各项技术性能,最后通过Weibull分布,分析了不同RET改性沥青混合料在不同失效概率下的疲劳性能。结果表明：RET的掺入提高了沥青的黏度和抗车辙因子,对沥青的高温性能有较大改善;通过掺入RET-SBS,增加了改性沥青中的黏性成分;相较于SBS改性沥青,RET-SBS改性沥青的表面粗糙度显著增大;RET改性剂能够明显改善沥青混合料的高温稳定性;RET与SBS改性剂复配,可有效弥补RET对沥青混合料低温性能的不足,明显改善沥青混合料的疲劳性能和高温长期稳定性。     

共混型热塑性弹性体的制备技术

以PP／EPDM-TPE为例,从共混、动态硫化／交联工艺和设备等方面介绍了共混型热塑性弹性体制备技术的发展状况。同时指出,反应型双螺杆挤出共混工艺是制备共混型TPE的发展方向。