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1、聚合物共混改性原理 聚合物纳米复合材料,张 琴,聚合物复合体系的分类,纳米概念的形成,早期,石墨、炭黑中的颗粒1959年,美国物理学家Richard Feynman提出“what would happen if we could arrange the atoms one by one the way we want them?”20世纪70年代康乃尔大学C.G.Granqvist&R.A.Buhrman 小组气相沉积制备纳米 20世纪80年代,原西德Gleiter首次制备金属纳米,提出纳米材料及其应用1981年,IBM发明AFM和STM,推动纳米技术发展20世纪80年代末期,日本丰田研究中心
2、制得PA6/粘土纳米复合材料,What nanocomposites are,Nanocomposites are made by mixing two or more phase,such as particles,layers or fibres,where at least one of the phases is in the nanometre size range.Because the building blocks making up the nanocomposites are therefore so close to the molecular scale,confine
3、ment and quantum effects result from the way that the blocks interact.Nanocomposites show properties not found in bulk materials,differentiating them from typical composites or filled-polymer systems.,Classification of nanocomposite,Polymer/inorganic nanocomposites,Polymer nanocomposites are general
4、ly defined as the combination of a polymer matrix resin and inorganic particles(particles,layers or fibres)which have at least one dimension(i.e.length,width,or thickness)in the nanometer size range,制备聚合物纳米复合材料的无机物的种类,纳米粒子(CaCO3、SiO2、TiO2、ZnO、Al2O3、Cr2O3)纳米纤维(碳纳米管、纤维素晶须、凹凸棒土)层状无机物,Layered host cryst
5、als susceptible to intercalation by a polymer,蒙脱土的化学通式:Nax(H2O)4(AL2xMgx)Si4O10(OH)2,分类:钠基蒙脱土(碱性土)钙基蒙脱土(碱土性土)天然漂白土(酸性土),蒙脱土的改性方法,人工钠化改型(悬浮液法、堆场钠化法、挤压法)酸活化方法(干法活化工艺、湿法活化工艺),湿法生产工艺:,干法生产工艺:,Structure of 2:1 layered silicates,蒙脱土的结构特征-天然的纳米结构,Cation-exchange reaction between the silicate and the alkyla
6、mmonium salt,蒙脱土族矿物具有离子交换性、吸水性、膨胀性、触变性、黏结性、吸附性等特性,插层剂的作用,利用离子交换的原理进入蒙脱土片层之间;扩张片层间距;改善层间的微环境;使蒙脱土的内外表面由亲水性转化为疏水性;增强蒙脱土片层与聚合物分子链之间的亲和性;降低硅酸盐材料的表面能。,常用的插层剂有烷基铵盐、季铵盐、吡啶类衍生物和其他阳离子型表面活性剂,聚合物/层状硅酸盐纳米复合材料特点,需要填料体积分数少;具有优良的热稳定性及尺寸稳定性;性价比高。,Polymer layered Nanocomposites preparation,In-situ intercalation poly
7、merization to intercalate the monomer and then take advantage of the hosts oxidising properties to induce polymerization Polymer intercalation from solution Polymer melt intercalation to mix the polymer and layered silicate together and then heat the mixture above the glass transition temperature(so
8、ftening point)of the polymer Exfoliation-adsorption Template synthesis,In situ Polymerization,Schematic representation of in-situ polymerization,聚合物大分子溶液插层工艺示意图,Schematic representation of melt intercalation,制备方法的改进,利用共聚物制纳米复合材料(PS、PMMA);利用聚合物催化剂制纳米复合材料(PS、PET);利用相容剂制纳米复合材料(PP);利用环状低聚物的开环聚合制纳米复合材料(P
9、C);硬质环氧树脂纳米复合材料的制备(硬质环氧树脂)。,Naoki Hasegawa,et al,Polymer 44(2003)29332937,a novel compounding process using Namontmorillonite water slurry for preparing novel nylon 6/Namontmorillonite nanocomposites,Naoki Hasegawa,et al,Polymer 44(2003)29332937,Layered Nanocomposite structure,PLS纳米复合材料微观结构的分类表,Sche
10、matic depicting the XRD patterns for various types of structures,The new properties of nanocomposites,Efficient reinforcement with minimal loss of ductility and impact strengthIncrease thermal stabilityIncrease flame retardant Improved gas barrier properties Improved ionic conductivityReduced therma
11、l expansion coefficientAltered electronic and optical properties,Properties of Nylon-6 layered silicate nanocomposites,Organoclay(wt%)dependence of HDT of neat PLA and various PLACNs.(b)Load dependence of HDT of neat PLA and PLACN7,TGA curves for polystyrene,PS and the nanocomposites,Proposed model
12、for the torturous zigzag diffusion path in an exfoliated polymerclay nanocomposite when used as a gas barrier,Comparison of combustion of Nylon 6,6 and Nylon6,6 nanocomposite with clay fraction of 5 wt.-%(Cloisite 15A)at external flux of 35 Kw/m2,PP及其纳米复合材料的热释放速率对比(热通量=35kW/m2),Real picture of biode
13、gradability of neat PLA and PLACN4 recovered from compost with time.Initial shape of the crystallizedsamples was 3*10*0.1 cm3.,Degree of biodegradation(i.e.CO2 evolution),and(b)time-dependent change of matrix Mw of neat PLA and PLACN4(MEE clay=4 wt%)under compost at(58+2)C,聚合物纳米复合材料的问题,无机相分布不规则;无机相形
14、态难控制;存在界面问题;分散方法需改进。,Morphology of layered silicate,Kinetics of polymer melt intercalation,Two steps for nanocomposite formation:Polymer transported from the agglomerate-polymer melt interface to the primary particlesPolymer melt penetrate to the edges of the crystallites The first step is limiting
15、step for polymer nanocomposites formation,Thermodynamic analysis,F=F(h)-F(h0)=E-TS F 0 indicate layer separation is favorable F 0 implies the initial unintercalated state is favorable S S chain+S polymer,Influence factors of polymer intercalation,Original properties of silicate Polymer architecturei
16、nteraction between surface and polymer a.Organically modified layered silicates surface b.Adding a fraction of functionalized polymersProcess condition,WAXD patterns of organically modified clay:(a)smectiteclay modified with C8,C12,and C16 phosphonium salt;(b)smectite,MMT,and mica clay modified with
17、 C16 phosphonium salt,Bright field TEM images of melt compounded nanocomposites containing,3 wt%MMT based on(a)HMW,(b)MMW,and(c)LMW N6,Schematic illustration of OMLS dispersion process in PP-g-MA matrix,Three cases involving the interplay during melt processing,Process condition,H.R.Dennis et al./Po
18、lymer 42(2001)95139522,Illustrates schematically how platelets peel apart under the action of shear,H.R.Dennis et al./Polymer 42(2001)95139522,The key of the formation of nanocomposites is:there are enough interaction between polymer and layer silicates so that the intercalation and exfoliation can
19、occur,X-ray diffraction scans for(a)nylon 6;(b)nylon 6/untreated mont.(c)Nylon 6/treated mont.(10wt%mont.),Crystallization behavior,Steady shear viscosity as a function of shear rate for a series of hybrids of PDMS/MMT,Rheology behavior,delaminated,intercalated,Temperature dependence of G;G and tan
20、d for N6 matrix and various N6CNs.,P.J.Yoon et al./Polymer 43(2002)67276741,纳米复合材料的表征方法,X-射线衍射法:测定层状化合物或层状硅酸盐材料的层间距激光光散射方法:测定超细颗粒的(或纳米粒子)的分布曲线TEM方法AFM方法(Atomic Force Microstropy)SEM与图像分析仪,利用X射线衍射测量蒙脱土层间距的原理图,Bragg方程:=2dsin,聚合物/无机纳米复合材料的应用 聚酰胺/层状硅酸盐纳米复合材料,有机粘土层间距与-氨基酸碳链长度的关系1:-氨基酸插层粘土2:-己内酰胺插层有机粘土(25
21、)3:-己内酰胺插层有机粘土(100),有机粘土的制备,Alkyl chain aggregation in layered silicates:(a)lateral monolayer;(b)lateral bilayer;(c)paraffin-type monolayer and(d)paraffin-type bilayer,原位聚合制备PA6/粘土纳米复合材料,-己内酰胺水解聚合反应示意图图中Pn表示生成的聚合物分子链的聚合度,合成粘土及PA6/粘土纳米复合材料的X射线衍射图谱,PA6/粘土纳米复合材料的TEM照片,普通PA6与PA6/合成粘土的WAXD谱线,普通PA6与PA6/合成
22、粘土的DSC曲线,普通PA6与n-PA6(4%)的流变曲线,普通PA6与n-PA6的性能对比,不同填充材料填充PA6时复合材料的弯曲模量对比,PA6与n-PA6材料薄膜对水、氧气的阻隔性能比较(1atm=101325Pa),应用,熔融插层制备PA6/层状硅酸盐纳米复合材料,聚合物熔体插层制备PA6/粘土纳米复合材料的流程图,PA6及其纳米复合材料的X射线衍射谱线 1:PA6;2:PA6/粘土纳米复合材料,PA6及其纳米复合材料的DSC升温曲线,PA6/粘土纳米复合材料的DSC降温曲线,蒙脱土填充量对PA6结晶度与过冷度的影响,蒙脱土的含量对n-PA6材料杨氏模量的影响,蒙脱土的含量对n-PA6
23、材料弯曲性能的影响,蒙脱土的含量对n-PA6材料冲击性能的影响,蒙脱土的含量对n-PA6材料热变形温度的影响,熔体插层PP纳米复合材料,TEM photograph of PP/MMT nanocomposite(5 wt%MMT content),TEM photographs of PP/MMT traditional composites,(a)PP-A(b)PP-B,SEM images of fractured surface at different mixing time,The WAXD profiles changes with the increase of mixing
24、time(PP:MI=8.0g/10min),shear,shear,Primary particles,agglomerates,crystallite,(a)particles became smaller under shear,Schematic of the formation of nanocomposite via melt intercalation,(b)polymer chains dispersion,(c)intercalation and exfoliation occur,Schematic of morphological development during b
25、lending,t=0 t=1min t=5min t=20min,or,(a)static(b)dynamic,TEM photographs of PP/MMT nanocomposites(MMT content:5wt%),Shear direction,2d-WAXD diagrams of pure PP and PP/MMT nanocomposites(5 wt%MMT)prepared at Tmelt=220,f=0.2 Hz,(a-1)PP,static(a-2)PP,dynamic,(b-1)PP-5,static(b-2)PP-5,dynamic,Halpin-Tsa
26、i continuum Equations,The theoretical tensile modulus at different N together with experimental data in the PP/MMT nanocomposites,stress-strain curves of PP/MMT nanocomposites,Engineering stress-strain curves,true stress-strain curves,stress-strain curves of PP/MMT nanocomposites,2d-WAXD diagrams of
27、 PP/MMT nanocomposites(3wt%MMT content)measured for indicated strain during stretching under load,PP PP-1 PP-3,PLM micrographs of the different samples crystallization at 130,Different crystallite data of the samples from SAXS,tp of the samples at different crystallization temperature,The DSC thermo
28、grams of samples,heating scan cooling scan,The various crystallization parameters of the samples from DSC,Application of PP nanocomposites,PP thin film for food packageEngineering PP plasticsfor Auto bumper and safety helmet,Application of PET,Synthetic fibersFilmsBottlesEngineering plastics,PET nan
29、ocomposites,PET nanocomposites for beer packaging,1.Huge market of beer packagingThere were 305 billion(305,000,000,000)beer containers all over the world in 2001.And the amounts are increasing stably every year.It had reached nearly 20million ton beer in China in 2002 which will overrun the U.S.A a
30、nd become the top one whose beer production arranged in the world.Every developed country are studying plastic beer bottle to occupy this huge market.,2.Necessity of developing plastic beer bottle,3.Status of PET beer packaging bottle,Advantage of PET packaging:lightweight(easy to transport)unbreaka
31、ble(hard to break up)transparent(you can see the inner object)nontoxic,odorless cheap The market of PET packaging material is booming up in recent year.,limits of PET for beer packaging:,not enough oxygen-barrier capability(oxygen gas transmission rate of PET is about 2.1x10-5cm3.mm/cm2.hr.atm,as th
32、e beer bottle its ORT must lower than 3.8x10-6cm3.mm/cm2.hr.atm)low heat-resistant(Bas sterilization of beer at 80)PET packaging materials made of general PET resin can not to contain oxygen-sensitive products.But modified PET can be used in beer bottle,it is the most important to improve the oxygen
33、-barrier capability.,Properties of PET layered silicate nanocomposites,高分子纳米复合材料的研究和应用是始自上世纪80年代,日本丰田中央研究院在此方面作出了开拓性的贡献。最早用于丰田车内部件的尼龙6纳米复合材料,但是由于价格的原因很快被放弃了。通用汽车公司在其2002年的两款新车GMC Safari和Chevrolet Astro 上采用了一种全新的材料聚丙烯/膨润土纳米复合材料制备的脚踏板(step-assist),这项技术创新获得了国际塑料工程师协会的大奖,对整个高分子纳米复合材料的发展有里程碑的意义。它标志着经过十几年
34、的研究与开发,高分子纳米复合材料开始进入大规模商业化应用的阶段。2001年在加拿大举行的Polymer Nanocomposites会议预测,到2020年Polymer Nanocomposites的规模将达到年产量3000万吨、价值650亿美元,而高分子/层状硅酸盐纳米复合材料将占据主要的市场份额。,聚合物纳米复合材料的应用,部分高分子纳米复合材料的提供厂商,主要应用领域,汽车(轻质、高强、高的热变形温度):Ube公司尼龙6纳米复合材料用于丰田汽车的变速带盖(timing belt cover);Unitika公司在尼龙6的聚合过程中加入合成云母得到尼龙6纳米复合材料用于三菱汽车的引擎盖;G
35、E塑料将碳纳米管添加于PPO/nylon合金来提高其导电性,用于静电喷涂。陶氏(Dow)公司的一项长期计划是-原位聚合方法制备高填充(10wt%)的聚丙烯纳米复合材料,作为汽车的半截构件使用,据称已初步取得乐观的结果。比利时的Kabelwerk Eupen公司在开发纳米膨润土添加的EVA作为电缆电线,这是基于添加后其燃烧释热释放速率的显著下降和优异的力学性能和化学稳定性;位于美国密歇根州的Exatec of Wixom,是一家由Bayer公司和GE塑料合资成立的一家公司,它正在开发可用于汽车涂层的纳米添加的PC料,希望提高PC的耐候性和耐磨性而不降低其透明性。,包装材料,Honeywell公司
36、提供含2%和4%纳米膨润土的尼龙6,可作为中等阻隔材料对氧气敏感产品的包装,其对氧气的阻隔性与尼龙6相比分别提高了3倍和6倍,同时还增加了膜的刚度、耐热性和透明度。Honeywell公司还设计了以纳米膨润土作为透过层,以特定尼龙作为氧气捕捉活性层的纳米复合材料。纳米膨润土的作用是保护氧气捕捉层以免其过早耗尽。用于三层结构的PET瓶,目标市场是啤酒瓶,。Nanocor公司与三菱瓦斯合作,将其牌号为Imperm的纳米膨润土加入到无定形的MDX6尼龙中,所得的纳米复合材料的的氧气组各行为PET的100倍,他作为三层PET瓶中的中间层,据称作为啤酒瓶的货架期可达到200天。Bayer公司将Nanocor的纳米膨润土用于尼龙6的浇注膜,用于多层包装、保护膜和药品的包装等。Ube公司将纳米膨润土加入到尼龙6/66的共混物中,用来作为汽车的燃油系统,据称2%纳米膨润土含量的尼龙6与未改性的尼龙6相比,对甲醇的阻隔性提高了5倍。,发展趋势预测,高分子/膨润土纳米复合材料1999-2009年预测(质量单位:百万英镑),