共查询到19条相似文献,搜索用时 203 毫秒
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采用比色法、热失重法等研究了不同镁铝摩尔比的水滑石(LDHs)对PVC糊热稳定性能的影响。结果表明。在镁铝比分别为2、3、4的样品中,镁铝比为2的LDHs对PVC的热稳定效果最佳;将其与传统的铅盐、有机锡稳定剂复配,均具有良好的协同效应。可以实现对PVC糊热稳定性能的控制。其中,PVC/Mg-Al LDHs/Sn以100:1.5:1.5(质量份数,下同)比例复合后的体系,不仅热稳定性能优于传统的铅盐体系,而且具有较低的糊黏度及较好加工流变性能。 相似文献
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采用盐碱共沉淀法制备镁铝水滑石,采用XRD、FT-IR和粒度分析等手段对合成样品进行分析和表征,利用静态热老化法和静态热稳定性实验研究了镁铝水滑石稳定剂在聚氯乙烯(PVC)中的热老化性能和热稳定性
能。实验结果表明:镁铝水滑石是良好的PVC热稳定剂和热老化剂,热稳定剂实验的最佳配方比为m(PVC)∶m(硬脂酸)∶m(镁铝水滑石)= 100∶2∶1.2;热老化实验的最佳配方为m(PVC)∶m[邻苯二甲酸二辛酯(DOP)]∶m(硬脂酸)∶
m(镁铝水滑石)=100∶70∶2∶2。 相似文献
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以镁铝碳酸根型水滑石MgAl-CO3-LDHs(LDHs)为前驱体,硬脂酸钠(NaSt)为改性剂,通过焙烧还原法在硬脂酸钠的溶液中制备硬脂酸钠改性水滑石LDHs-NaSt,采用X射线衍射仪(XRD)、傅里叶转变红外光谱仪(FTIR)和扫描电镜(SEM)对结构进行表征,并研究不同改性剂加入量条件下得到的改性水滑石对聚氯乙烯(PVC)热稳定性能的影响。结果表明,在氮气保护下,焙烧后的水滑石可以成功复原,硬脂酸钠对LDHs的改性为表面改性,但影响复原水滑石的结晶度。改性水滑石可以改善PVC的初期着色性和长期热稳定性,随着改性剂浓度的增大,当NaSt与LDHs质量比为1∶4时,静态热老化时间可以达到370 min,比未改性水滑石热稳定性能提升了61%。 相似文献
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采用共沉淀法制备了不同锌含量的硼酸三丁酯掺杂钙铝水滑石(CaAlZn-C_(12)H_(27)BO_3LDHs),并将其应用于聚氯乙烯(PVC)弹性体中,通过与无机硼酸掺混钙铝水滑石、钙铝锌水滑石进行应用对比,考察不同水滑石对PVC复合材料热稳定性、阻燃性、力学性能及不同锌含量对其残炭率的影响。结果表明:CaAlZn-C_(12)H_(27)BO_3LDHs形貌规整,峰形尖锐;随着锌含量的增加,PVC复合材料残炭率出现先上升后下降的趋势,且Ca~(2+)∶Al~(3+)∶Zn~(2+)最佳物质的量比为2∶1∶2;硼、锌离子掺杂水滑石对PVC复合材料的热稳定性、阻燃性及力学性能均优于硼酸锌/水滑石机械混合物。 相似文献
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以氢氧化镁[Mg(OH)2]和乙酰丙酮为原料,乙醇为溶剂,通过一步异相沉淀转化法制备配合物乙酰丙酮镁[Mg(acac)2],用作聚氯乙烯(PVC)辅助热稳定剂。首先,采用XRD、FTIR、TG对产物进行了结构表征,然后通过静态热老化试验和刚果红试验,对乙酰丙酮镁的热稳定性能进行研究。结果表明,成功制备出产物乙酰丙酮镁,且含有2个结晶水;在PVC中,当主效热稳定剂与辅助热稳定剂的质量比为3∶5时,PVC 的热稳定时间长达57min。该生产技术克服了乙酰丙酮镁传统合成方法产率低、操作过程复杂、污染等缺点,制备的产物乙酰丙酮镁与主效热稳定剂具有良好的协同作用,可以有效提高PVC的热稳定性能。 相似文献
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通过刚果红法实验研究了不同种类和用量的二氧化钛(TiO2)对使用复合铅盐稳定剂的硬质聚氯乙烯(PVC—U)脱氯化氢反应的影响,同时研究了不同用量的TiO2对使用不同热稳定剂的PVC—U脱氯化氢反应的影响。结果表明:①在复合铅盐稳定体系中,金红石型TiO2会导致PVC—U的热稳定性的下降,而锐钛型TiO2会提高PVC—U的热稳定性;②金红石型TiO2后期的包覆处理也对PVC—U的热稳定性有影响;③金红石型TiO2(R930)在复合铅盐热稳定体系中会导致PVC—U的热稳定性下降,而在Ca/Zn热稳定体系中,则能提高PVC—U的热稳定性。 相似文献
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《无机盐工业》2018,(11)
采用共沉淀-离心-水热法制备了结晶度高的镁-铝-镧三元类水滑石(MgAlLa-CO_3-LDHs),采用SEM、XRD对产物结构进行表征。探索了共沉淀温度、共沉淀时间、水热温度、水热时间对产物结构的影响。研究发现:在n(M~(2+))∶n(M~(3+))=2∶1、n(La~(3+))∶n(Al~(3+))=1∶23、溶液pH≥10的情况下,70℃共沉淀反应2 h,再在150℃下水热反应10 h,制备出典型层状结构、高纯度、晶型完整且层板堆积有序性高的镁-铝-镧三元类水滑石。将其作为稳定剂用于聚氯乙烯(PVC)加工,通过静态热烘箱实验、刚果红实验,研究其对PVC热稳定性能的影响。结果表明:镁-铝-镧水滑石能够大幅度提高PVC的热稳定性能。 相似文献
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Shi Yi Zhan‐Hong Yang Sheng‐Wei Wang Dong‐Ren Liu Su‐Qin Wang Qing‐Yan Liu Wei‐Wei Chi 《应用聚合物科学杂志》2011,119(5):2620-2626
MgAlCe‐CO3 layered double hydroxides (LDHs) with different Ce/Al molar ratios were prepared by the constant pH coprecipitation method. The synthesized materials were characterized by XRD and FTIR, and the results showed that the hydrotalcite‐like materials have a layered structure. Different LDHs as stabilizers were mixed with PVC resin. The tests of thermal aging and Congo red for the PVC composites were carried out at 180 ± 1°C, respectively. The results showed when MgAlCe‐CO3‐LDHs were added into PVC as single thermal stabilizers, 3 phr (parts per hundred PVC resin) MgAlCe‐CO3‐LDH with Ce/Al (molar ratio) = 0.075 has a better stabilizing effect on PVC than others. Compared with single thermal stabilizers (LDHs or Ca/Zn systems), the composite thermal stabilizers including 0.3 g calcium stearate (Cast2), 1 g zinc stearate (Znst2), and 3 g MgAlCe‐CO3‐LDH have significantly enhanced the thermal stability of PVC sample, and the thermal stable time was over 190 min. The main reason could be concluded to the special structure of Ce element and the synergistic reaction among MgAlCe‐CO3‐LDHs, Cast2, and Znst2. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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采用共沉淀法制备了十二烷基硫酸根插层MgAlLa类水滑石(LDHs),采用X射线衍射分析(XRD)和红外光谱(FT-IR)表征.将LDHs添加到PVC树脂中,采用刚果红法、烘箱变色法、氧指数法,垂直燃烧法(UL-94)等研究其单独使用的热稳定性、阻燃性和力学性能,并测定与其他阻燃剂复配时的阻燃性和力学性能.结果表明,在100份PVC中添加3份LDHs可延长材料的热稳定时间和初期白度,添加30份LDHs时可改善阻燃性,对力学性能影响不明显;与聚磷酸铵(APP)协同效果较好,比例为1/4时,材料的极限氧指数(LOI)提高到29.5%,垂直燃烧等级为94V-0,力学性能显著增强. 相似文献
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An effective stabilizing system for poly (vinyl chloride) (PVC)/clay composites was established. Different types of stabilizers, i.e., organotin, calcium/zinc, barium/zinc, and an epoxy costabilizer, were investigated. The combination of the organotin stabilizer and the epoxy costabilizer was the most effective stabilizing system. Different grades of Cloisite nanoclays were investigated. Cloisite Na did not cause premature degradation of PVC. Cloisite 10A strongly accelerated the degradation of PVC because of the presence of excess surfactant, while a PVC/Cloisite 30B system showed much better thermal stability because there was less organic impurity in the Cloisite 30B. Phosphonium‐modified clays were also prepared. They showed better thermal stability than ammonium‐modified clays, but the drying conditions still need to be optimized in order to produce a dispersible clay powder. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers 相似文献
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采用自行研制的成核晶化隔离法制备了不同Cu2+、Zn2+和Al3+物质的量比的层状双金属氢氧化物(LDHs)。通过X射线衍射(XRD)、红外光谱(FT-IR)、热重-差热分析(TG-DTA)、程序升温还原(TPR)及X光电子能谱(XPS)等研究手段对LDHs及其在500 ℃焙烧产物的组成、结构和表面化学状态进行了分析。结果表明,在焙烧产物中均存在一定形式相互作用的CuO-ZnO-Al2O3复合金属氧化物,Cu2+、Zn2+和Al3+之间的配比影响LDHs结构和热稳定性及其焙烧产物的组成和还原性能。 相似文献
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Metal chlorides formed from metal stabilizers under processing conditions have an influence on the thermal stability of PVC. Zinc chloride, e. g., has a strong destabilizing effect, whereas lead chloride behaves almost indifferently. Alkyltin chlorides however, have a stabilizing effect in as much as they cause a significant retardation of the thermal dehydrochlorination rate of PVC. Using 1-chlorobutene-2 as model substance, a chloro allyl isomerization could be proved caused by organotin chlorides under certain conditions. These results support a complex chemical isomerization concept to explain the stabilizing effect of organotin chlorides on PVC. 相似文献