稀土钛偶联剂对CaC03改性及其在PE-LLD中的应用研究

采用万能试验机、转矩流变仪和旋转黏度计等研究了新型稀土钛偶联剂对不同粒径重质碳酸钙（CaCO3）的偶联处理及其对PE—LLD／CaCO3复合体系的力学性能和流变性能的影响。结果表明，稀土钛偶联剂改性的不同粒径CaCO3填充的复合体系的力学性能和流变性能得到很大改善；其中，稀土钛偶联剂处理粒径18μm重质CaCO3效果最好，当偶联剂含量为1．2％（质量分数，下同）时，复合体系的断裂伸长率、拉伸强度和拉伸弹性模量分别比未改性的提高了14．7％、12．5％和10．3％，而最大扭矩和平衡扭矩比未改性的分别降低了11．4％和9．6％；其改性效果均优于钛酸酯和铝酸酯偶联剂。实验表明稀土钛偶联剂处理的CaCO3在非极性液体石蜡中有较好的分散性和相容性。     

改性勃姆石对聚丙烯性能影响研究

将勃姆石用酞酸酯偶联剂（TC-114）进行活化改性处理,将其与聚丙烯（PP）进行熔融挤出得到PP/改性勃姆石复合材料,采用热重分析仪、差示扫描量热仪、极限氧指数测试仪、锥形量热仪等探究改性后勃姆石对PP性能的影响。结果表明,经过偶联剂处理的勃姆石填充PP后所得的复合材料的弯曲强度与纯PP对比的提高了14.4 %,冲击强度提升了30.6 %,而与未改性勃姆石填充的复合材料比弯曲强度提高了6.9 %,冲击强度提升了5.7 %,且断裂伸长率相较于未改性的复合材料提升4倍;改性勃姆石填充聚丙烯复合材料的熔体流动速率、热稳定性以及极限氧指数相较于纯PP都有较大程度提升;改性后的勃姆石有增强聚丙烯力学性能性能的效果,并且随着填入量的增加,热稳定性和阻燃性能都随之提高。     

碳酸钙／聚丙烯复合材料的力学性能对比研究

研究了无机刚性材料纳米或微米碳酸钙对聚丙烯(PP)的填充改性以及利用钛酸酯偶联剂对纳米碳酸钙进行表面处理后,对于碳酸钙/聚丙烯复合材料体系的力学性能的影响.结果表明,纳米碳酸钙/聚丙烯复合材料的力学性能明显优于微米碳酸钙/聚丙烯复合材料的力学性能;钛酸酯偶联剂改性处理纳米碳酸钙粒子后,其复合体系的冲击强度和断裂伸长率有明显的提高.     

稀土复合偶联剂对氢氧化镁的表面改性研究

对超细无机阻燃粉体氢氧化镁进行表面改性可大大改善其与有机高聚物的相容性和加工流动性.选择稀土偶联剂/螯合磷酸酯钛偶联剂作为氢氧化镁的复合改性剂,采用湿法改性处理氢氧化镁.通过表面分析技术测定改性氢氧化镁粉体表面性质;利用差热分析技术(DTA)测定其热起始分解温度;利用傅里叶变换红外光谱仪(FT-IS)证实了氢氧化镁表面改性层的存在.通过实验,得到稀土偶联剂/螯合磷酸酯钛偶联剂复合改性剂表面处理氢氧化镁的最佳工艺条件:浆料质量分数为30%,改性剂稀土偶联剂与螯合磷酸酯钛偶联剂质量比为1.9∶ 1,改性剂用量为2.5%,改性温度为80 ℃,搅拌速率为760 r/min,改性时间为30 min.在此条件下,改性氢氧化镁的吸油值从0.499 7 g/g降至0.336 5 g/g,活化指数从0上升到99.86%,热起始分解温度从341.1 ℃升至366.5 ℃.     

偶联剂对线性低密度聚乙烯/水滑石体系力学和流变性能影响

采用钛酸酯偶联剂NDZ-201、硅烷偶联剂KH-570、硬脂酸和硬脂酸-稀土偶联剂,对水滑石(LDHs)进行表面改性处理,通过X射线衍射和红外光谱表征了改性前后LDHs的结构变化;并研究了不同种类偶联剂及其含量对LDHs填充LLDPE复合体系的力学性能和流变性能的影响.结果表明:4种偶联剂均可以实现LDHs表面改性,并且不会改变LDHs层状结构;改性后LLDPE/LDHs复合材料的断裂伸长率和流变性能得到提高;其中用4%硬脂酸改性LDHs时,LLDPE/LDHs复合材料的断裂伸长率为160%,平衡扭矩为8 N·m.     

氢氧化铝微粉表面原位组合化学改性的研究

利用黏度法研究了以金属偶联剂[M(OR)n]和9种不同链长与构型的含羧基或羟基有机物对氢氧化铝表面进行原位组合化学改性的效果。研究表明:具有柔性链基结构的改性剂和金属偶联剂组合改性的效果较好;在液体石蜡中改性氢氧化铝最大填充量由未改性时的43%提高到了改性后的62%,体系黏度才大幅度增加。     

改性氢氧化铝的制备及其在油相中的粘度行为研究

研究了以硬脂酸、铝酸酯偶联剂改性和烷基酚醛树脂、丁腈橡胶为改性剂经表面原位组合化学方法处理的3种改性氢氧化铝，在液体石蜡和邻苯二甲酸二辛酯中体系粘度随不同改性方法、填充量、温度、烘干和放置时间等因素的变化。研究结果表明，3种改性的氢氧化铝在液体石蜡和邻苯二甲酸二辛酯中均比未改性的具有明显的降粘效果，在邻苯二甲酸二辛酯体系中都具有快速而稳定的抗沉降性。在液体石蜡体系中铝酸酯偶联剂改性的氢氧化铝的降粘效果最好。表面原位组合化学改性的氢氧化铝在邻苯二甲酸二辛酯中的降粘效果最好，且在上述2种体系中抗沉降性最好。它们敞开放置于空气中吸湿后，通过80℃烘干2～4h可恢复改性效果。     

稀土偶联剂对氢氧化镁的表面改性及其阻燃应用

采用稀土偶联剂、硅烷偶联剂及钛酸酯偶联剂对氢氧化镁进行表面改性,考察了偶联剂用量、处理温度、时间对氢氧化镁表面改性效果的影响.通过黏度、表面活化度等指标对改性效果进行了表征.结果表明:稀土偶联剂对氢氧化镁的改性效果较其他二者要好,并确定了稀土偶联剂的改性的最佳工艺条件.采用改性后的氢氧化镁进行了填充聚乙烯研究,结果表明:当稀土改性后的氢氧化镁的填充量为140份时,复合材料的阻燃性达到了UL94 V-0标准,力学性能较好;通过SEM观察表明:稀土改性后的氢氧化镁在LLDPE基体树脂中的分散性明显优于未改性的.     

聚磷酸铵粉体改性及对聚丙烯力学性能的影响

采用氯化铝和氨水溶液为原料,在液相体系中生成氢氧化铝,使其包覆在阻燃剂聚磷酸铵(APP)颗粒的表面,制备了表面包覆氢氧化铝的聚磷酸铵复合颗粒(N-APP)。通过调整合适的反应参数对工艺条件进行优化设计,确定了最佳反应条件。同时对最终产品的表面形貌、抗水性以及热稳定性等进行了表征,扫描电镜(SEM)结果表明,经包覆改性后,粉体的表面粗糙度明显增加,并且,改性后产品N-APP(6#)的接触角由未改性时的8.9°提高到118.9°,具有较好的疏水性能;热失重分析结果表明,包覆改性在一定程度上提高了产品的热稳定性。将经包覆改性后的产品在聚丙烯(PP)填充应用,与添加未改性APP的PP复合材料相比,添加包覆改性产品的PP复合材料的力学性能明显提升。     

纳米CaCO3填充PTFE复合材料力学性能的研究

通过机械搅拌、冷压成型烧结方法,制备了纳米碳酸钙填充改性聚四氟乙烯(PTFE)复合材料;并研究了复合材料的物理机械性能。结果表明未改性的纳米碳酸钙显著提高了复合材料的弹性模量、断裂伸长率和冲击强度,其中断裂伸长率最高可达800%,冲击强度亦可提高到纯PTFE的233%;但复合材料的拉伸强度有所降低。改性后的纳米碳酸钙效果并不是很理想,主要是表面改性剂高温分解存在的影响。     

稀土偶联剂（REC）对PP／Mg（OH）2体系性能的影响

研究了稀土偶联剂（ＲＥＣ）处理对ＰＰ／氢氧化镁（Ｍｇ（ＯＨ）２）体系的燃烧性能、流动性能、力学性能及老化性能的影响。未经处理的Ｍｇ（ＯＨ）２在填充量超过５０％时,ＰＰ／Ｍｇ（ＯＨ）２体系的ＯＩ≥２８．５,但这时冲击强度不足纯ＰＰ的３０％,熔体流动速率低于０．６ｇ／１０ｍｉｎ;而填料用２．５％（重量）ＲＥＣ处理后,填充量为５０％的体系冲击强度接近纯ＰＰ,ＭＦＲ达２．８ｇ／１０ｍｉｎ;ＲＥＣ对Ｍｇ（Ｏ     

PP/滑石粉导热绝缘复合材料的制备与性能研究

采用聚丙烯(PP)为基体,不同粒径滑石粉为填料,通过双螺杆挤出机挤出制备导热绝缘的PP滑石粉复合材料。在滑石粉用量为3O%的条件下,探讨了粒径分别为3.6,6,12,30,50 μm的滑石粉对PP猾石粉复合材料的热导率、体积电阻率、力学性能和结晶性能的影响。结果表明,随着滑石粉粒径的减小,复合材料的拉伸强度和弯曲强度呈先增大后减小的变化趋势,而其热导率则呈先减小后增大的变化趋势。填充粒径为12μm的滑石粉时,复合材料的拉伸强度和弯曲强度达到最大值,分别为29.92MPa和52.58MPa,比纯PP分别提高了5.5%和12.8%。填充粒径为50μm的滑石粉时,复合材料的热导率最大,达到0.3237W/(m*K),比纯PP提高了32.7%。填充1:l的粒径为12μm和30μm滑石粉混合物时,PP复合材料的热导率为0.3184W/(m*K),高于相应的填充单一粒径滑石粉的PP复合材料。此外,所制备的PP滑石粉复合材料的体积电阻率均大于10^8Ω*cm     

The effect of surface modification of aluminium hydroxide on the crystallisation behaviour of aluminium hydroxide filled polypropylenes

Composites based on polypropylene (PP) (homopolymer and impact modified copolymer) and surface modified aluminium hydroxide (Al(OH)₃) have been studied using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Filler surface modifiers used included 2-dodecen-1-yl succinic anhydride (DDSA) as a dispersant and a commercial silane based coupling agent system (BA Chemicals S21). Treatment of the Al(OH)₃ with DDSA led to a considerable reduction of the capacity of the filler to nucleate crystallisation in the PP and, in some composites, promoted growth of β-PP. With the S21 treatment, however, a nucleation effect was still apparent, despite encapsulation of the filler particles with the elastomeric phase in the case of the impact modified PP. DSC and XRD studies indicated that with the untreated filler nucleation was directly associated with the filler surface. However, with the S21 treated filler this was not the case and PP nucleation was random and/or flow induced with no association with the filler surface.     

硅烷偶联剂对氢氧化镁表面改性及其在聚丙烯中的应用

选用具有相同亲水基团的4种硅烷偶联剂对工业级氢氧化镁进行常温湿法表面改性,并与聚丙烯(PP)熔融混合制得掺杂氢氧化镁质量分数为35%的复合材料,以SEM,FT-IR等手段对氢氧化镁及复合材料进行表征,考察了不同硅烷对复合材料阻燃性能和力学性能的影响。结果表明,硅烷偶联剂湿法改性可以提高氢氧化镁的分散性和与材料的相容性,改善氢氧化镁/PP的力学性能,但对阻燃性能影响不大;十二烷基三甲氧基硅烷在水相中稳定性好,可以较多地包覆于氢氧化镁表面,改性后材料的悬臂梁缺口冲击强度提高50%,断裂伸长率提高6倍,达到很好的改性效果。     

Physical and mechanical properties of Al(OH)3/polypropylene composites modified by in situ‐functionalized polypropylene

Al(OH)₃/polypropylene (PP) composites modified by in situ‐functionalized polypropylene (FPP) were prepared by a one‐step melt‐extrusion process. The effect of in situ FPP on the crystallization and melting behavior, melt‐flow index, limiting oxygen index, thermal degradation, mechanical properties, and fracture morphology of Al(OH)₃/PP composites was studied. Formation of in situ FPP resulted in a decreased crystallization temperature and melting point of PP in the composites, an increased melt‐flow index, and improved tensile and flexural strengths of Al(OH)₃/PP composites, whereas the thermal degradation behavior and limiting oxygen index was not been influenced. The impact strength of the Al(OH)₃/PP composites modified by in situ FPP depended upon the content of the initiator, dicumyl peroxide, and the monomer, acrylic acid. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2850–2857, 2002; DOI 10.1002/app.10269     

Preparation and evaluation of composites containing polypropylene and cotton gin trash

Composites of polypropylene (PP) and cotton gin trash (GT) were prepared to enhance the utilization of agro-based materials in industrial products. GT was modified by two methods: toluene washed only, and toluene washed and treated with maleic anhydride-grafted polypropylene (MAPP). These GT samples were extruded with PP, including MAPP and ethylene/vinyl acetate copolymer in various weight ratios (32 composites total). The PP composites displayed tensile strengths close to that of the neat PP, and exhibited higher values of tensile modulus and lower elongation at break than the neat PP. Based on DSC measurements, the PP composites containing 10 wt% GT exhibited two crystalline regimes, while those containing 20 wt% GT were similar in crystallinity to that of the neat PP. The composites were also characterized using SEM, TGA, water absorption tests, and contact angle measurements. These composites represent a more sustainable alternative to neat, fossil fuel-based PP.     

Nonisothermal crystallization kinetics of polypropylene‐layered double hydroxide composites: Correlation with morphology

In this work the effect of nanofiller on nonisothermal crystallization behavior of composites based on polypropylene (PP) was investigated by differential scanning calorimetry. The materials were prepared by melt mixing. Both an alkyl sulfonate salt modified layered double hydroxide (LDH) and an unmodified LDH were used as nanofillers and both PP and PP/polypropylene grafted with maleic anhydride (PP‐g‐MA) blend were used as matrices. The morphology of composites was investigated by X‐ray diffraction and transmission electron microscopy. No exfoliation was noticed in all prepared composites, but the hybrid materials showed an intercalated structure. The thermal properties and crystallization behavior were studied by conventional differential scanning calorimetry. In particular, the kinetic crystallization parameters were obtained using the modified Avrami equation for a nonisothermal process, whereas the activation energy of the global crystallization process was estimated using the Kissinger equation. The Avrami parameters suggest a significant effect on the crystallization of PP for the composites containing both the organically modified LDH and PP‐g‐MA. The results indicate a complex crystallization process of PP and evidence that the crystallization process can not be only explained by intercalation phenomenon, but the constrain effect ofpolymer chains on the filler surface and/or betweenthe filler clusters should play a significant role. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Thermal oxidative degradation kinetics of PP and PP/mg (OH)2 flame‐retardant composites

The thermal stability and thermal oxidative degradation kinetics of polypropylene (PP) and flame‐retardant PP composites filled with untreated and treated magnesium hydroxide (MH) in air were studied by thermogravimetric analysis (TGA). The effect of the heating rate in dynamic measurements (5°C–30°C/min) on kinetic parameters such as activation energy was also investigated. The Kissinger and Flynn–Wall–Ozawa methods were used to determine the apparent activation energy for the degradation of neat PP and flame‐retardant PP composites. The results of TGA showed that the addition of untreated or treated MH improved the thermal oxidative stability of PP in air. The kinetic results showed that the apparent activation energy for degradation of flame‐retardant PP composites was much higher than that of neat PP, suggesting that the flame retardant used in this work had a great effect on the mechanisms of pyrolysis and combustion of PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1978–1984, 2007     

Mechanical properties and fracture morphology of Al(OH)3/polypropylene composites modified by PP grafting with acrylic acid

Al(OH)₃/polypropylene (PP) composites modified by polypropylene grafted with acrylic acid (FPP) were prepared by melt extrusion. Effect of PP grafting with acrylic acid on mechanical properties and fracture morphology of Al(OH)₃/polypropylene composites were investigated. Although incorporation of Al(OH)₃ reduced the mechanical properties of PP, addition of FPP increased the mechanical properties of Al(OH)₃/PP composites. It is suggested that addition of FPP improve the dispersion of Al(OH)₃ and the interfacial interaction between filler and matrix. Mechanical properties of Al(OH)₃/FPP/PP composites depend on the grafting rate and the content of FPP. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2617–2623, 2001     

Preparation of 4,4′‐diaminostilbene‐2,2′‐disulfonic acid intercalated LDH/polypropylene nanocomposites with enhanced UV absorption property

The UV absorber 4,4′‐diaminostilbene‐2,2′‐disulfonate (DASDSA) has been successfully intercalated into an inorganic host Zn₂Al layered double hydroxide (Zn₂Al‐DASDSA LDH), which is expected to lead stabilization and protection of this thermally unstable UV absorber. Using a modified solvent mixing method, polypropylene/AMO‐Zn₂Al‐DASDSA LDH (PP/AMO‐LDH; AMO = aqueous miscible organic treated) nanocomposites were prepared using unmodified PP at various LDH loadings of 0.2–4 wt%. The characterization data indicated that AMO‐LDH nanoparticles were evenly dispersed within the PP matrix because of the excellent compatibility between PP and the AMO‐LDH. The resistance to thermal degradation of PP/AMO LDH nanocomposites was significantly increased even with very low LDH loadings. The 50% weight loss temperature (T _0.5) of PP was increased by 43°C with 4 wt% LDH. UV analysis demonstrated that adding AMO‐Zn₂Al‐DASDSA LDH could significantly enhance the UV absorption capacity of PP. For the enhancement of the photo‐stability of PP, the performance of AMO‐Zn₂Al‐DASDSA was much better than the control material Zn₂Al‐NO₃. POLYM. COMPOS., 38:1937–1947, 2017. © 2015 Society of Plastics Engineers