CPE／PS共混物相容剂CPE—g—St的表征

采用水相悬浮法合成了氯化聚乙烯(CPE)接枝苯乙烯(St)共聚物(CPE-g-St)。以N,N-二甲基甲酰胺(DMF)为萃取剂可将接枝共聚产物中的聚苯乙烯(PS)均聚物萃取干净。红外(IR)光谱测定法结果证明,CPE链上已接技有PS支链。扫描电镜(SEM)谱图和动态粘弹性能说明CPE-g-St可显著增加CPE和PS两相间的相容性并形成界面层。CPE-g-St的存在还大大提高CPE/PS共混物的力学性能。     

熔融接枝反应改进聚烯烃粘结性的研究

选用丙烯酸（AA）和马来酸酐（MAH）等为接枝改性单体，以DCP（过氧化二异丙苯），DTBP（二叔丁基过氧化物）为引发剂，研究了不同工艺条件下聚烯烃树脂接枝改性后与极性材料（如金属铝箔，尼龙等）的粘结性能以及加入其他树脂稀释后对其性能的影响。研究结果表明，对不同类型的聚烯烃树脂，选用合适的接枝改性单体，引发剂和工艺条件，可以制备出与极性材料粘结性能良好的改性树脂；通过适当的稀释，在提高（对PP类）或不明显降低（对PE类）粘结性能的情况下，可以匀化改性树脂，调整改性树脂的流动性能，此类改性树脂可用作挤出涂覆或共挤出复合的粘结剂，聚烯烃与极性聚合物合金的相容剂或聚烯烃与无机填料共混物的分散剂。     

PC/PS/PC-g-PS 共混体系流动性能的研究

研究了聚碳酸酯（ＰＣ）／聚苯乙烯（ＰＳ）共混体系及辐射接枝共聚物ＰＣｇＰＳ增容ＰＣ／ＰＳ共混体系的转矩流变性能和剪切流变性能。结果表明，少量的ＰＳ的加入能明显改善ＰＣ熔体的流动性，共混物呈现出假塑性流体的流动行为．而ＰＣｇＰＳ的加入则能增强这种影响作用．     

Characterization of mesoporous alumina prepared by surface alumination of SBA-15

Mesoporous aluminas of controlled pore sizes were synthesized by multiple grafting of Al isopropoxide in organic solvents on mesoporous silica SBA-15. These materials were characterized by N₂ physisorption, TEM, XRD, ²⁷Al NMR and their surface chemical properties were probed by DRIFT, cumene cracking and MoO₃ thermal spreading. The results show that the chemical nature of the Al-grafted materials varies continuously with the number of grafting from pure silica to pure alumina. Typically, after three graftings, this original method of synthesis allows one to prepare ordered mesoporous aluminas with specific surface areas above 300 m² g⁻¹ and a narrow pore size distribution centered on ca. 60 Å. In addition to the characterizations, different models were developed to understand the evolution of the specific surface area and to discard a possible pore blocking.     

低气味低VOC玻纤增强聚丙烯材料的研制

以聚丙烯(PP)树脂为基体,PP接枝马来酸酐(PP-g-MAH)为相容剂,纳米氧化锌和纳米二氧化钛为复合气味吸收剂,经双螺杆挤出机制备了玻璃纤维(GF)增强PP材料,并分别研究了各组分对材料力学性能和气味等级的影响。结果表明,相容剂PP-g-MAH为GF增强PP材料气味的主要来源,在提高气味等级方面,选用相容剂时,固相接枝工艺比熔融接枝工艺的好,且接枝率不宜太高。在选用PP粒料、接枝率为1.2%的固相接枝PP-g-MAH以及纳米氧化锌和纳米二氧化钛复合气味吸收剂的基础上,制备了低气味和低挥发性有机化合物的GF增强PP材料,其拉伸强度为62 MPa,弯曲强度为76 MPa,缺口冲击强度为8.5 k J/m~2,由其制备的汽车空调电机风扇叶轮产品的气味等级达到了Q/JLY J711061–2009标准的7级要求。     

Oxidation‐grafting surface modification of waste silicone rubber composite insulator powder: Characterizations and properties of EPDM/modified waste powder composites

In order to broaden the applications of waste silicone rubber composite insulator powder (WSP), modified waste powder (WSP‐KH570) was prepared by a two‐step treatment process involving improved surface oxidation approach by using acidic H₂O₂ solution and subsequently grafting of KH570. Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR‐ATR) analysis revealed the presence of KH570 on the powder surface. The result was confirmed by thermogravimetric analysis (TGA). Blends of ethylene propylene diene monomer (EPDM) with WSP‐KH570 were prepared. The effects of WSP‐KH570 on mechanical properties and thermal properties of the blends were investigated. The WSP‐KH570 showed an observed improvement in tensile strength and elongation at break of EPDM/WSP‐KH570 blends compared with corresponding compositions of EPDM/WSP blends. The TGA cure showed that EPDM filled with WSP‐KH570 had higher thermal stability at 210–380 °C than EPDM/WSP. Dynamic mechanical analysis indicated EPDM and WSP‐KH570 were better miscible with the blend ratio (90/10). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45438.     

The effect of the incorporation of polystyrene‐based chain extenders on the properties of the shape memory polyurethanes

In this work, the idea of modulating the shape memory properties of polyurethanes by changing their macromolecular architecture through the incorporation of polystyrene‐based moieties was investigated. To study these effects, poly(styrene‐co‐maleic anhydride) (SMA) was incorporated during the synthesis of PU as a potential chain extender. Two sample groups were produced: (i) PU, produced with hydrazine as a chain extender and (ii) PU_SMA, produced with the addition of SMA instead of hydrazine. The results suggest that the SMA incorporation in the PU_SMA chains occurred by the reaction between NCO groups of the PU and maleic anhydride (MA) of the SMA. The presence of SMA was useful in modulating the structure of PU by reducing the soft segment crystallinity and molar mass. These changes in the structure and macromolecular architecture due to the presence of SMA moieties in PU chains led to pronounced improvements in strength, toughness, and the shape recovery ratio. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44471.     

The grafting reaction of epoxycyclohexyl polyhedral oligomeric silsesquioxanes with carboxylic methoxypolyethylene glycols and the properties of composite solid polymer electrolytes with the graftomer

A novel organic–inorganic hybrid of epoxycyclohexyl polyhedral oligomeric silsesquioxane (e‐POSS)–grafted carboxylic methoxypolyethylene glycols (mPEG‐COOH), that is, a POSS‐mPEG graftomer, was synthesized. The grafting reaction of e‐POSS and mPEG‐COOH was characterized by Fourier transform infrared (FTIR) and ¹H‐NMR spectroscopy. Then the graftomer was used to develop new composite solid polymer electrolyte (SPE) films with a carboxylated nitrile rubber–epoxidized natural rubber (XNBR‐ENR) self‐crosslinked blend system as a dual‐phase polymer matrix. The self‐crosslinked reaction of the XNBR‐ENR matrix was investigated using ATR‐FTIR. The morphology of the SPE films and the distribution of lithium salt were investigated using field emission scanning electron microscopy and X‐ray diffraction, and the result illustrated that the addition of POSS‐mPEG could promote and accelerate the dissociation of LiClO₄. The best effect within the range of this study was achieved when 25 phr POSS‐mPEG was involved. The differential scanning calorimetry analysis proved that the glass‐transition temperature of the composite SPE films was reduced with the increase of POSS‐mPEG. The ionic conductivity of the composite SPE films was investigated by electrochemical impedance spectroscopy. The highest ionic conductivity in this study of 2.57 × 10^?5 S cm^?1 was obtained with 25 phr POSS‐mPEG loading. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44460.     

PA66/EPDM-g-MAH/CaCO_3复合材料的性能

采用熔融挤出过程中改变螺杆转速和添加引发剂的复合引发方法制备了马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH),将其单独或与CaCO_3混合后改性聚酰胺66(PA66)。通过滴定分析、红外表征和熔体流动速率(MFR)测定等方法研究了175℃条件下螺杆转速对EPDM-g-MAH的MFR和接枝率的影响。探讨了接枝物和CaCO_3对PA66力学性能、热变形温度的影响。研究结果表明,改变螺杆转速可以有效控制接枝物凝胶含量(1%),提高接枝率和MFR;当接枝物用量为30份时,PA66/EPDM-g-MAH复合材料的简支梁缺口冲击强度为34.24 k J/m2,是纯PA66的3.89倍;当CaCO_3用量小于15份时,两种CaCO_3与EPDM-g-MAH均能够协同增韧PA66,当PA66/EPDM-g-MAH/CaCO_3配比为100/30/10时,加入超细活性重质CaCO_3及纳米CaCO_3的复合材料的简支梁缺口冲击强度均达到最大值,分别为纯PA66的4.35倍和4.10倍,超细活性重质CaCO_3的作用优于纳米CaCO_3。超细活性重质CaCO_3用量为20份时,PA66/EPDM-g-MAH复合材料的弯曲强度、热变形温度及MFR最佳,分别为59.42 MPa、81.6℃及9 g/(10 min)。     

丙烯酸酯接枝改性天然橡胶增韧聚乳酸

通过在天然橡胶(NR)分子链上接枝甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA),制备了三种丙烯酸酯接枝改性NR:NR-g-PMMA,NR-g-PBA和NR-g-(PMMA,PBA)。采用核磁共振氢谱对三种接枝物进行了化学结构鉴定。将接枝改性后的NR和未改性的NR与PLA采用哈克密炼机熔融共混,分别制备了PLA/NR,PLA/NR-gPMMA,PLA/NR-g-PBA和PLA/NR-g-(PMMA,PBA)共混物,研究了接枝改性NR和未改性NR含量对共混物力学性能和热性能的影响。各共混物的拉伸弹性模量和拉伸强度均随接枝改性NR和未改性NR含量的增加而降低,断裂伸长率和缺口冲击强度随接枝改性NR和未改性NR含量的增加而提高。其中,PLA/NR-g-PBA共混物的断裂伸长率和缺口冲击强度比其它共混物提高的幅度大,当NR-g-PBA的质量分数为5%时,PLA/NR-g-PBA共混物的断裂伸长率达到78%,缺口冲击强度为5.2 k J/m2,而纯PLA的断裂伸长率仅为7.7%,缺口冲击强度为2.5 k J/m2,说明NR接枝分子柔顺性较高的BA更有利于促进其与PLA共混物的韧性提高。热分析结果表明,PLA/NR-gPBA共混物的热稳定性相比于纯PLA也有所提高。