【作者】 江娟；

【导师】 李谷；

【作者基本信息】 中山大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 聚丙烯是一种与我们的日常生活密切相关的通用树脂,由于其比重小,易加工,较高的力学性能等特点而在汽车、日用消费品以及包装等方面受到广泛的应用。但其缺口敏感性强,冲击强度低,特别是在低温下,其性脆。因此,降低其低温脆性,提高其综合力学性能以及制备具有特定功能的聚丙烯塑料成为一种研究趋势。分子筛是一类结晶态的硅酸盐或硅铝酸盐,由硅氧四面体或铝氧四面体通过氧桥键相连而形成的分子尺寸大小(通常为0.3-2.0 nm)的孔道和空腔体系。其独特的结构特征及性质在于具有长程有序的孔结构和窄的孔径分布以及高孔隙率、大比表面积等。分子筛作为一种无机材料,其主要应用于催化剂载体、吸附剂等方面。但将分子筛包覆金属氧化物后再作为无机填料改性聚合物的研究相比还较少。氧化锌是一种应用前景较为广泛的无机材料。纳米氧化锌对紫外线吸收能力强,对UVA(320-400nm)和UVB(280-320nm)均有屏蔽作用。纳米氧化锌还具有一定的抗菌除臭作用,可用来生产除臭抗菌材料。除此之外,纳米氧化锌无毒无味,稳定性好,对皮肤无刺激,本身为白色,可以根据时间应用加以着色,加工方便。由于这些特性主要应用于电子和光学仪器、气敏计、压敏电阻和抗菌抗老化材料等方面。本文利用分子筛的吸附性能将氧化锌填充于分子筛,根据不同的后处理得到三类改性分子筛样品:①仅孔内稳定吸附氧化锌的分子筛(ZnO-in)②孔内外均稳定吸附氧化锌的分子筛(B-ZnO)③内、外表面稳定吸附氧化锌和外表面不稳定吸附的游离氧化锌共存的分子筛(T-ZnO)。用荧光光谱、X射线衍射(XRD)等对改性分子筛进行表征。再采用熔融混炼法制备未改性分子筛/PP(S/PP)、改性分子筛/PP复合材料(ZnO-in/PP、B-ZnO/PP、T-ZnO/PP)复合材料母粒。将复合材料母粒于平板硫化机压膜制备薄膜样品。用傅立叶转换红外光谱(FTIR)、紫外光谱、DSC、荧光光谱、XRD、偏光显微镜(POM)、抗菌实验来对粉末和复合材料进行研究。研究结果表明:1.氧化锌已经成功吸附进分子筛孔内,分子筛外表面也会吸附氧化锌,在制备不同类的样品时后处理是关键,不同的后处理得到不同的样品。2.分子筛及不同改性分子筛对PP起到异相成核的作用,分子筛含量增加,复合材料的结晶峰温度均有提高,而且分子筛的加入可以诱导β晶型的生成,当分子筛含量在3%左右时β晶含量最高。3.负载氧化锌的分子筛/PP复合材料薄膜具有一定的抗金黄色葡萄球菌和大肠杆菌的作用,而抗金黄色葡萄球菌效果更好。三种改性分子筛粉末中,ZnO-in粉末样品的抗菌效果最好,T-ZnO粉末抗菌效果最差;而三类改性分子筛/PP薄膜样品中,T-ZnO /PP复合薄膜的抗菌效果最好,ZnO-in/PP薄膜抗菌效果最差。4.分子筛的加入对PP紫外老化和热老化有影响,未改性分子筛S、ZnO-in能抑制PP短时间内的紫外老化,不能抗长时间紫外老化,B-ZnO和T-ZnO能抗长时间的紫外老化,在照射时间达到90h后,PP、S/PP和ZnO-in/PP薄膜样品变得极脆。S、ZnO-in和B-ZnO能抑制PP在加工过程中的热老化,而T-ZnO无此作用。更多还原

【Abstract】 Polypropylene(PP),as a universal resin, is closely related with our daily lives. It is widely used in the automotive, consumer products and packing fields because of its low density, processed easily and high mechanical properties. But there is a weak point of the low impact strength especially at low temperatures. Therefore, reducing the low-temperature brittleness, improving their mechanical properties and the preparation of polypropylene plastic with a specific function is becoming a trend.Molecular Sieves, a class of crystalline silicate or aluminosilicate, are channel and cavity systems of molecular size, typically 0.3-2.0 nm, formed by silicate or aluminum tetrahedra through oxygen bridge bond, which have the characteristics of molecular screening. Its unique structure and properties are a long-range order of pore structure, narrow pore size distribution, high porosity, and large surface area, etc. Molecular Sieve, as an inorganic material, mainly used in catalyst carriers, adsorbents etc. However, the study of the Molecular Sieve encapsulating metal oxide as inorganic fillers of polymers is still few.Zinc oxide is an inorganic material with more extensive application prospect. Nano-Zinc oxide reveals a strong ability of absorbing UV and shielding effect of UVA (320nm-400nm) and UVB (280nm-320nm) especially. Nano-Zinc oxide also has some antibacterial and deodorizing effect, which can be in the products of deodorizing and antibacterial materials. In addition, nano-zinc oxide is a material of non-toxic, tasteless, good stability and colored easily according to the practical application. So it is mainly used in electronic and optical devices, gas meter, pressure-sensitive anti-aging resistance and antibacterial material, etc.In this paper, three different Molecular Sieves loading zinc oxide are prepared by different post-processing. The first one is the Molecular Sieves adsorpting zinc oxide only in the hole, the second is the Molecular Sieves adsorpting zinc oxide both inner surface and outer surface of the Molecular Sieves stably, and the last is the mix of the second and pure zinc oxide. Fluorescence spectroscopy and X-ray diffraction (XRD) are introduced to investigate the different Molecular Sieve samples. The composites of Molecular Sieves/PP with different Molecular Sieves content are prepared by melt mixing and made into films. The composites films are investigated by Fourier transform infrared spectroscopy (FTIR), DSC, Fluorescence Spectrum, XRD, polarizing microscopy (POM), and antibacterial experiments. The experimental results are as follows:1. The adsorption of zinc oxide has been successfully into the molecular sieve pore. The adsorption to zinc oxide of external surface will also happen. Therefore, different post-processing of Molecular Sieves after absorption is the key when the different samples are prepared.2. Molecular Sieves play a role of heterogeneous nucleation on the PP. the crystallization peak temperature of composite materials have increased with the increased content of Molecular Sieve. And the addition of Molecular Sieve can induce the formation ofβcrystalline. The highest contentβ-crystal can be obtained in 3wt% Molecular Sieves/PP.3. The composites of modified Molecular Sieves/PP show better anti--Staphylococcus aureus than Escherichia coli role to some extent. The ZnO-in powder sample works best to Staphylococcus aureus and Escherichia coli and T-ZnO worst among three samples. Among three films T-ZnO /PP has the best antibacterial effect and ZnO-in/PP worst.4. The addition of Molecular Sieves has an effect on UV and thermal aging. The samples S and ZnO-in can restrain the aging of PP caused by UV for short times, but it is invalid for long hours. However, B-ZnO and T-ZnO can play for a long time in terms of inhibiting UV aging of PP. For thermal aging of PP in process, S、ZnO-in and B-ZnO inhibit the occurrence of thermal degradation in process ,but T-ZnO do not work.更多还原