表面改性剂对CaCO3:Eu3+荧光粉发光性能的影响

采用微波共沉淀法制备了CaCO3:Eu3+红色荧光粉,然后分别用硬脂酸和钛酸酯偶联剂(TC-114)对其进行改性,研究改性前后荧光粉的结构和发光性能的变化。激光粒度和X射线衍射分析表明,经硬脂酸改性后的荧光粉粒径有所增加,而经钛酸酯偶联剂改性后的荧光粉粒径有所减小,改性前后结构未发生变化。红外光谱与热重分析表明,硬脂酸和钛酸酯偶联剂与荧光粉表面羟基发生了化学键合。荧光光谱测试表明,经硬脂酸改性的CaCO3:Eu3+红色荧光粉荧光强度增强,而经钛酸酯偶联剂改性后其荧光强度明显减弱,可能是由改性剂自身结构以及改性前后荧光粉表面的羟基数量和猝灭中心数量不同所致。     

不同表面改性剂对α-高强石膏粉/HDPE复合材料性能的影响

采用硅烷偶联剂(KH550、KH560、KH570)、硬脂酸和钛酸酯偶联剂NDZ201对α-高强石膏粉进行改性,然后与高密度聚乙烯(HDPE)混合挤出制备α-高强石膏粉/HDPE复合材料,考察不同表面改性剂对α-高强石膏粉/HDPE复合材料力学性能的影响。通过测定吸油值以及利用傅立叶红外光谱仪(FTIR)和扫描电子显微镜(SEM)表征改性效果,最后检测复合材料力学性能。结果表明,上述表面改性剂均与α-高强石膏粉发生化学键合作用,且硬脂酸对α-高强石膏粉的改性效果最佳,其在HDPE中分散均匀,两者间界面相容性较好,硬脂酸改性后的复合材料拉伸强度与断裂伸长率均有提高,但弯曲强度与缺口冲击强度变化不大。     

机械力化学法改性白云石粉体的研究

采用机械力化学法改性工艺,以钛酸酯、铝酸酯和硬脂酸3种不同的改性剂对白云石粉体进行表面改性。通过活化指数和接触角等性能的表征,考察了各表面改性剂的改性效果;同时利用红外光谱分析对表面改性机理进行了探讨。研究表明,硬脂酸和铝酸酯的改性效果要优于钛酸酯,改性后白云石粉体表面具有良好的亲油疏水性,钛酸酯、铝酸酯和硬脂酸3种改性剂最佳的用量分别为白云石粉体质量的1%、3%和2%,此时改性白云石粉体的活化指数分别达到74.09%、98.5%和94.4%;接触角分别达到130.5°、137.3°和139.4°。红外光谱分析表明,改性后的白云石粉体颗粒表面官能团发生了变化,改性剂在白云石粉体颗粒表面吸附并可能发生了化学键合作用。     

秸秆纤维的改性对PBS复合材料性能的影响

采用改性剂改性后的玉米秸秆纤维增强聚丁二酸丁二醇酯(PBS),利用热压工艺得到了秸秆纤维/PBS复合材料;研究了苯甲酸、硬脂酸、硅烷、壳聚糖及乙酸5种改性剂对经超声波处理后的秸秆纤维/PBS复合材料性能的影响;采用EDS、SEM、FTIR及WXRD对改性前后的纤维及复合材料进行了分析.研究结果表明:5种改性剂对纤维均有改性效果,苯甲酸质量分数为2%-3%时,复合材料力学性能最优.     

重质碳酸钙粉体改性研究

采用硬脂酸、钛酸酯、十二烷基苯磺酸钠、磷酸酯及其不同配比对CaCO3进行表面改性处理.通过对改性效果分析,讨论各改性剂的改性特点及最佳配比,寻找碳酸钙的改性最佳工艺.对碳酸钙表面改性,按活性大小改性剂的排序为:硬脂酸＞钛酸酯＞磷酸酯＞十二烷基苯磺酸钠,且复合改性剂比单一改性剂对碳酸钙表面改性效果明显.     

纤维改性对小麦秸秆纤维/PBS复合材料性能的影响

利用NaOH对小麦秸秆纤维进行处理,同时采用了不同的蒸煮助剂和改性剂,以改变纤维自身物理性能及其表面化学性质。将改性纤维与聚丁二酸丁二醇酯(PBS)共混,制备了秸秆纤维/PBS复合材料,并通过X射线能谱仪(EDS)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)对改性前后的纤维进行了分析和观测,研究分析了助剂和改性剂对复合材料性能的影响。结果表明:秸秆纤维经NaOH/4%Na2SO3处理,以及碱处理纤维经钛酸酯偶联剂NDZ201、环氧树脂E44改性,所得纤维增强复合材料的性能较为优异。     

双层包覆改性碳酸钙在高填充聚酯中的应用

以聚对苯二甲酸己二酸丁二醇酯(PBAT)树脂为基材,以50%表面改性的CaCO3为填充物制备出高填充复合材料。通过对CaCO3表面改性剂的种类以及复配研究,采用双层包覆技术制备出力学性能较好的高填充全生物降解复合材料。采用0.5%KH560和0.5%钛酸酯102双层包覆法表面改性碳酸钙,制备成复合材料拉伸强度达到20.28 MPa,相对于未改性的复合材料拉伸强度提高了39%,相对于单层KH560和钛酸酯102表面改性技术制备成的复合材料拉伸强度分别提高了16.8%和26.6%。并通过动态流变学的Cole-Cole理论研究了不同改性方法在PBAT/CaCO3复合材料中对两相间相容性以及弹性模量的影响,为高填充复合材料的开发与应用奠定了基础。     

钛酸钾晶须增强不饱和聚酯树脂的力学性能

应用硅烷偶联剂、硬脂酸和钛酸酯偶联剂对钛酸钾晶须(PTW)进行表面处理,考察了偶联剂种类和钛酸钾晶须用量对不饱和聚酯树脂(UP)/PTW复合材料力学性能的影响,用扫描电子显微镜观察了纯UP及UP/PTW复合材料的断面形貌。结果表明,用3种偶联剂表面改性的PTW能够显著提高UP的力学性能,其中以硬脂酸为最好。经过硬脂酸表面改性的PTW能够较好地分散在树脂基体中,当硬脂酸表面改性的PTW质量分数为2.5%时,UP/PTW复合材料的拉伸强度和冲击强度分别提高约57%和39%。     

硅灰石的表面改性对其填充PTFE复合材料摩擦学性能和力学性能的影响

利用钛酸酯偶联剂、硅烷偶联荆和硬脂酸对硅灰石进行表面改性,并对改性后的硅灰石进行类似与聚四氟乙烯(PTFE)复合加工过程中的热处理,测量其处理前后填料与水的接触角的变化,同时还考察了3种改性剂对PTFE/硅灰石复合材料的摩擦学性能和力学性能的影响.结果表明,硅烷偶联剂改性的硅灰石经过热处理后与水的接触角由64.5°增加到126.5°,表面能接近PTFE基体,相比其它改性荆能够更有效地提高复合材料的摩擦学性能和力学性能.     

碳酸钙改性研究

用硬脂酸、钛酸酯、十二烷基苯磺酸铀、聚乙烯醇及聚乙二烯及其不同配比，对CaCO3进行表面处理。通过对改性效果分析，讨论各改性剂的改性特点及最佳配比，并通过硬脂酸对氧化铁红改性做对比，比较吸油值的变化。     

表面处理对可生物降解黄麻/PLA复合材料结构和性能的影响

采用注塑成型法制备了生物降解黄麻短纤维增强PLA复合材料,通过力学性能测试及SEM,探讨了碱处理、碱和硅烷偶联剂KH550同时处理对复合材料结构和性能的影响。结果表明:两种处理方法均能够增加黄麻纤维的表面粗糙度,但碱和偶联剂KH550同时处理的效果要优于碱处理,且KH550改善了黄麻短纤维与PLA树脂之间的界面黏结性能提,高了黄麻/PLA复合材料的拉伸强度和弯曲强度。     

Moisture uptake and hygroexpansion of wood fiber composite materials with polylactide and polypropylene matrix materials

Effects of butantetracarboxylic acid (BTCA) modification, choice of matrix, and fiber volume fraction on hygroexpansion of wood fiber composites have been investigated. Untreated reference wood fibers and BTCA‐modified fibers were used as reinforcement in composites with matrices composed of polylactic acid (PLA), polypropylene (PP), or a mixture thereof. The crosslinking BTCA modification reduced the out‐of‐plane hygroexpansion of PLA and PLA/PP composites, under water‐immersed and humid conditions, whereas the swelling increased when PP was used as matrix material. This is explained by difficulties for the BTCA‐modified fibers to adhere to the PP matrix. Fiber volume fraction was the most important parameter as regards out‐of‐plane hygroexpansion, with a high‐fiber fraction leading to large hygroexpansion. Fiber‐matrix wettability during processing and consolidation also showed to have a large impact on the dimensional stability and moisture uptake. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

聚乳酸木塑复合材料增韧改性研究进展

对使用增容剂、弹性体、偶联剂改性,改变木粉粒径以及结晶形态等提高聚乳酸(PLA)木塑复合材料韧性的方法进行了综述,并对PLA木塑复合材料的增韧改性研究进行了展望。     

Effect of surface modifiers and surface modification methods on properties of acrylonitrile–butadiene–styrene/poly(methyl methacrylate)/nano‐calcium carbonate composites

Nano‐calcium carbonate (nano‐CaCO₃) was used in this article to fill acrylonitrile–butadiene–styrene (ABS)/poly(methyl methacrylate) (PMMA), which is often used in rapid heat cycle molding process (RHCM). To achieve better adhesion between nano‐CaCO₃ and ABS/PMMA, nano‐CaCO₃ particles were modified by using titanate coupling agent, aluminum–titanium compound coupling agent, and stearic acid. Dry and solution methods were both utilized in the surface modification process. ABS/PMMA/nano‐CaCO₃ composites were prepared in a corotating twin screw extruder. Influence of surface modifiers and surface modification methods on mechanical and flow properties of composites was analyzed. The results showed that collaborative use of aluminum–titanium compound coupling agent and stearic acid for nano‐CaCO₃ surface modification is optimal in ABS/PMMA/nano‐CaCO₃ composites. Coupling agent can increase the melt flow index (MFI) and tensile yield strength of ABS/PMMA/nano‐CaCO₃ composites. The Izod impact strength of composites increases with the addition of titanate coupling agent up to 1 wt %, thereafter the Izod impact strength shows a decrease. The interfacial adhesion between nano‐CaCO₃ and ABS/PMMA is stronger by using solution method. But the dispersion uniformity of nano‐CaCO₃ modified by solution method is worse. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

聚乳酸/剑麻复合材料流变性能表征

利用转矩流变仪测量流变特性的方法,表征了不同剑麻纤维含量下,聚乳酸(PLA)/剑麻复合材料的流变性能,并测量实验后纤维的长度和宽度、PLA分子量,分析剑麻纤维含量和转速对复合材料体系中纤维长度的影响,以及PLA降解情况。结果表明,复合材料的非牛顿指数在纤维含量为10%左右出现峰值,并进一步随含量的增加而减小。复合体系中,刚性剑麻纤维受到来自于转子、聚合物和纤维之间的作用力,纤维被剪短,长径比减小;聚乳酸会受到转速和纤维含量的影响发生降解,这些因素都会影响PLA/剑麻复合材料的流变性能。     

Effects of a new compatibilizer system on the flexural properties of wood–polyethylene composites

A novel wood–plastic compatibilizer system containing a paper wet‐strength agent as a wood‐binding domain and stearic anhydride as a polyethylene (PE) binding domain was investigated. Treatment of wood flour with a commercial paper wet‐strength agent Kymene® 557H (simply called Kymene) before the mixing of PE and the wood flour increased the modulus of rupture (MOR) and the modulus of elasticity (MOE) of the resulting wood–PE composites. Addition of stearic acid in the mixing of PE and the wood–Kymene mixture further increased the MOR and MOE. Stearic anhydride was even more effective than stearic acid in the increase of the MOR and MOE. Compared to wood–PE composites without a compatibilizer, the stearic anhydride–Kymene compatibilizer system increased the MOR by about 33% and the MOE by about 40%. The stearic anhydride–Kymene compatibilizer system gave a slightly lower MOR, but higher MOE than those of the commercially used compatibilizer (maleic anhydride‐grafted polypropylene). The compatibilization mechanisms were proposed as follows: Kymene not only bound to wood fibers, but also strengthened and stiffened the wood fibers. Stearic anhydride formed covalent linkages such as ester and amide with the Kymene‐consolidated wood fibers and the long hydrocarbon chain of the stearic anhydride bonded to the PE matrix through entanglements and/or cocrystallization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3667–3672, 2004     

氧化锌晶须表面改性及表征

采用湿法表面化学改性法，用硅烷和钛酸酯偶联剂对氧化锌晶须(ZnOw)进行了表面改性；考察了溶剂、pH值、温度及分散时间对硅烷类偶联剂改性效果的影响，采用活化指数、接触角以及傅立叶变换红外光谱对改性结果作了表征。同时将改性后的ZnOw填充到线性低密度聚乙烯(LLDPE)中，测试了复合材料的机械性能。实验结果表明，硅烷和钛酸酯偶联剂均能用于ZnOw的表面改性，其最佳改性条件不同，获得最佳改性效果的偶联剂用量也不同。经ND-42改性的ZnOw填充到LLDPE中，复合材料的弯曲强度大幅度提高。     

Cellulose fiber‐reinforced polylactic acid

Polymer composites from polylactic acid (PLA) and two types of cellulose fibers obtained either by acid hydrolysis of microcrystalline cellulose (HMCC) or by mechanical disintegration of regenerated wood fibers (MF) were prepared and characterized. To enhance the compatibility of the cellulose fibers with PLA matrix, a surface treatment based on 3‐aminopropyltriethoxysilane (APS) was performed. The Fourier Transform Infrared (FTIR) spectroscopy was used to determine the chemical groups involved in the surface modification reaction. The silanization treatment resulted in different modifications on both types of cellulose fibers because of their different structural and morphological characteristics. The composites were prepared by incorporating 2.5% of the treated or untreated HMCC and MF into a PLA matrix using a melt‐compounding technique. An improved adhesion between the two phases of the composite materials was observed by scanning electron microscopy thanks to treatment. The dynamic mechanical thermal analyses showed that both untreated and silane treated fibers led to an improvement of the storage modulus of PLA in the glassy state. A higher enhancement of the storage modulus in the case of PLA/HMCC composites than the composites containing MF was obtained as a result of the high aspect ratio of these fibers which allows better matrix‐to‐filler stress transfer. Furthermore, the storage modulus of PLA composites was enhanced by silanization even at higher temperatures especially after thermal treatment. The cellulose fibers addition in PLA matrix modified significantly the relaxation phenomenon as observed in tan δ curves, emphasizing strongly modified molecular mobility of PLA macromolecules and crystallization changes. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers.     

偶联剂对 PPS/PA66/T-ZnOw 复合材料力学性能的影响

采用硅烷偶联剂KH-560和钛酸酯偶联剂TM-38S对四针状氧化锌晶须(T-ZnOw)进行表面改性,制备了相应的聚苯硫醚(PPS)尼/龙(PA)66/T-ZnOw复合材料,研究了两种偶联剂及其复合体系对T-ZnOw表面改性效果和相应复合材料力学性能的影响,并利用扫描电子显微镜对复合材料的断面形态进行了观察。结果表明,钛酸酯偶联剂TM-38S对T-ZnOw的表面改性效果要优于硅烷偶联剂KH-560;两种偶联剂均提高了复合材料的拉伸强度、断裂伸长率和缺口冲击强度,但对复合材料的弯曲强度影响不大。其中TM-38S改性T-ZnOw与PPS/PA66复合后所得材料的力学性能优于KH-560改性T-ZnOw的材料。两种偶联剂的复合体系虽然可以弥补KH-560副反应对T-ZnOw表面改性的不利影响,但对改善复合材料力学性能的协同作用不明显。     

纳米碳酸钙性质对聚氯乙烯复合材料界面及性能的影响

选择了不同的表面处理剂对纳米CaCO₃进行表面改性. 研究了不同表面处理剂对CaCO₃/PVC纳米复合材料微观结构、界面结合强度、力学性能及加工性能的影响.研究表明,钛酸酯偶联剂处理可使纳米CaCO₃颗粒在PVC基体中达到良好分散,明显改善纳米CaCO₃颗粒与PVC基体之间的界面结合,并提高其界面结合强度.力学性能和流变性能研究表明,钛酸酯处理的纳米CaCO₃填充PVC具有更高的拉伸强度、冲击强度以及更低的平衡转矩, 而且CaCO₃/PVC复合材料的冲击韧性在填充量为20%(mass)时达到最大值26.5 kJ•m^-2,是纯PVC的4倍.