纳米碳酸钙对丁腈橡胶性能影响研究

为了研究纳米材料对橡胶性能的影响,以丁腈橡胶为基体材料,纳米级碳酸钙和常规碳酸钙为添加剂,对混炼工艺条件及纳米级和常规碳酸钙对丁腈橡胶性能的影响进行了研究。试验结果表明,纳米级碳酸钙可以大大提高丁腈橡胶的性能,不只作为增量填充剂,与常规碳酸钙的相容性比较好,但是在混炼过程中,必须充分加工以保证其在胶料中均匀分布。     

纳米无机粒子补强天然橡胶的研究(Ⅰ)纳米CaCO3/天然橡胶复合材料的研究

CaCO3是天然橡胶重要的补强性白色填充剂,同时纳米CaCO3粒子的超细化,使其结构发生巨大变化,表现出优异的补强天然橡胶的性能。本文综述了纳米CaCO3制备技术、改性以及补强橡胶的研究进展。     

纳米碳酸钙对RTV硅橡胶性能的影响

比较了纳米碳酸钙和轻质碳酸钙对室温硫化硅橡胶的机械性能和工艺性能的影响。结果表明，轻质碳酸钙只是常规的增量填充剂，纳米碳酸钙可以提高硅橡胶的交联密度和机械性能；但起始粘度增大，工艺性能下降。     

碳酸钙分散状态对硅橡胶流变性能的影响

使用3种纳米活性碳酸钙为填料制备室温硫化硅橡胶材料,通过透射电子显微镜观察碳酸钙在硅橡胶中的分散状态,分析碳酸钙分散状态对其流变性能的影响。结果表明,碳酸钙在硅橡胶中的分散状态与其二次团聚程度有关,填料的团聚与网络结构化均会使硅橡胶的储能模量产生显著变化,温度扫描也能反映碳酸钙在硅橡胶中的分散状态。     

纳米碳酸钙/二氧化硅复合粒子的制备及其在丁苯橡胶中的应用

将纳米碳酸钙的制备和表面包覆工艺融为一体,以硅酸钠为无机硅源,采用溶胶沉淀法制备出具有核壳结构的纳米碳酸钙/二氧化硅复合粒子,在纳米碳酸钙的表面包覆了一层致密的二氧化硅膜。采用TEM、红外光谱（FT-IR）、TG、XRD、BET、吸油值测定等手段对复合粒子的大小、形貌、化学组成、结构及表面性质进行了分析和表征。将复合粒子填充于丁苯橡胶,能显著提高丁苯橡胶（SBR）硫化胶的拉伸性能和撕裂性能。当填充量为75份时,拉伸强度最大,为13.6 MPa。     

Electrical conductivity and mechanical properties of polyaniline/natural rubber composite fibers

Electrically conducting elastomer fibers based on natural rubber (NR) and up to 10% w/w polyaniline (PANI) in its emeraldine base (EB) form were fabricated by a wet spinning process. The resulting fibers at various PANI contents were doped by immersion in aqueous HCl solution, which converted the PANI to the electrically conductive emeraldine salt (ES) form. The morphology of the composite fibers was studied by scanning electron microscopy (SEM). PANI particles were inhomogeneously distributed in the NR matrix. The electrical conductivity of the fibers increased with the increasing PANI‐ES content and leveled off at a value of around 10^?3 S/cm at PANI‐ES concentration of 5% w/w. The fibers retained most of their elasticity upon doping, while the tenacity was somewhat reduced. Gratifyingly, the electrical conductivity of the new elastomer fibers was preserved upon elongational deformation, even if strains as large as 600% were applied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

纳米碳酸钙丁腈橡胶母炼胶的制备及性能评价

采用乳液法制备了丁腈橡胶（NBR）/纳米碳酸钙（NCC）共沉橡胶,并对其性能进行了评价。基本性能实验结果表明：与NBR相比,共沉胶焦烧时间略有降低,正硫化时间略有增加,最大扭矩明显提高,共沉胶具有优异的基本物理性能;工业配方配合显示：共沉胶具有优异的基本物理性能、耐热空气老化性能以及耐热油性能;共沉胶成本明显降低,具有良好的应用前景。     

超声波在碳化法制备纳米碳酸钙中的应用

测试了超声波和氢氧化钙悬浮液波美度对碳化法制备的碳酸钙粒径的影响。结果表明 ,超声波可使碳酸钙的粒径由 10 0nm左右减小到 2 0nm左右 ,且粒径更均匀 ,晶形更规则 ,分散性更好 ;并且氢氧化钙悬浮液波美度越低 ,所得碳酸钙的粒径越小。     

Mechanical and flame‐retarding properties of styrene–butadiene rubber filled with nano‐CaCO3 as a filler and linseed oil as an extender

A nanosize CaCO₃ filler was synthesized by an in situ deposition technique, and its size was confirmed by X‐ray diffraction. CaCO₃ was prepared in three different sizes (21, 15, and 9 nm). Styrene–butadiene rubber (SBR) was filled with 2–10 wt % nano‐CaCO₃ with 2% linseed oil as an extender. Nano‐CaCO₃–SBR rubber composites were compounded on a two‐roll mill and molded on a compression‐molding machine. Properties such as the specific gravity, swelling index, hardness, tensile strength, abrasion resistance, modulus at 300% elongation, flame retardancy, and elongation at break were measured. Because of the reduction in the nanosize of CaCO₃, drastic improvements in the mechanical properties were found. The size of 9 nm showed the highest increase in the tensile strength (3.89 MPa) in comparison with commercial CaCO₃ and the two other sizes of nano‐CaCO₃ up to an 8 wt % loading in SBR. The elongation at break also increased up to 824% for the 9‐nm size in comparison with commercial CaCO₃ and the two other sizes of nano‐CaCO₃. Also, these results were compared with nano‐CaCO₃‐filled SBR without linseed oil as an extender. The modulus at 300% elongation, hardness, specific gravity, and flame‐retarding properties increased with a reduction in the nanosize with linseed oil as an extender, which helped with the uniform dispersion of nano‐CaCO₃ in the rubber matrix. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2563–2571, 2005     

Effects of Sm3+/PMAA on mechanical and thermal properties of natural rubber latex film

Samarium carbonate [Sm₂(CO₃)₃] was taken as the source of Sm³⁺, and methyl acrylic acid (MAA) was employed as the precursor to prepare polymethacrylic acid (PMAA). The mixture of Sm₂(CO₃)₃ and PMAA was marked as “SmP.” The SmP prepared under different conditions was added to natural rubber (NR) latex to prepare NR/SmP films. The influence of the polymerization temperature of MAA and the amount of SmP on the mechanical properties and structure of NR/SmP films were analyzed. The results show that polymerization temperature has significant effect on the mechanical properties of NR/SmP film; lower temperature is benefit to improve modulus and rigidity, whereas higher temperature helps maintain good elasticity. Compared with neat NR, addition of 5-phr Sm₂(CO₃)₃ results in a 30%–37% increase of tensile strength. Furthermore, the glass transition temperature (T_g) can also be increased by the addition of SmP; and the tan δ curves of all samples exhibit only one transition peak and indicate no phase separation between SmP and NR matrix. The influence of SmP on the structure and morphology of NR was explored by Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy analysis; and the results show that SmP can be dispersed uniformly in the NR latex when loading of Sm₂(CO₃)₃ is lower than 20 phr.     

纳米CaCO3/天然胶乳医用制品性能的研究

将表面处理过的纳米CaCO3按不同比例（1％，2％，3％，4％，5％，6％，8％）分别加入浓缩天然胶乳。硫化后，采用离子沉积胶凝法制备医用制品试样，然后研究其力学性能、热氧老化性能的变化。结果显示，加入纳米CaCO3的试样的扯断伸长率和拉伸强度均高于末加入纳米CaCO3的试样，其中3％纳米CaCO3／天然胶乳医用制品性能综合性能最佳。     

滑石粉及CaCO3对HDPE的共复合研究

在反应性偶联剂及助偶联剂存在下,将CaCO3或滑石粉对高密度聚乙烯（HDPE）进行复合时,随复合粉体含量的增加,CaCO3复合体系表现为拉伸强度下降但冲击强度大幅度增加,滑石粉复合体系则表现为拉伸强度有较大的增加但冲击强度有较大的下降;将滑石粉和CaCO3进行共复合时,可以同时发挥片状滑石粉的增强作用和近球状CaCO3的增韧作用,得到综合力学性能较好的复合材料,但其配合比、粉体总添加量及助偶联剂添加量将对体系的力学性能产生较大的影响;各体系冲击断面的扫描电子显微镜照片所显示的微观形状和其力学物性有较好的对应,证明在共复合体系中,CaCO3既能通过偶联剂及助偶联剂的作用对HDPE产生较好的增韧效果,又能对滑石粉的分散起到一定的促进作用,使体系的拉伸强度有所提高。     

砖红壤/天然胶乳复合胶膜的制备与性能研究

研究了砖红壤对天然胶乳的补强作用。将砖红壤原土中的细粒子制成悬浮液,加入预硫化天然胶乳中,制备砖红壤/天然胶乳复合胶膜,并分析胶膜的结构特性、力学性能和交联密度等。结果表明,砖红壤粒子在橡胶相中分散均匀,砖红壤细粒子对天然胶乳具有优异的补强效果,硫化胶膜的拉伸强度和撕裂强度均有大幅度的提高,这是由于砖红壤的加入能够促进橡胶的硫化,砖红壤中的氧化铁能够与橡胶分子链中的不饱和双键结合,提高了砖红壤在橡胶相中的分散性,使二者形成良好的界面结合。     

Transport properties of natural rubber latex layered clay nanocomposites

Natural rubber latex layered clay nanocomposites were prepared with low loadings of nanoclay using conventional compounding technique. A higher loading of clay resulted in processing difficulties due to viscosity build up. X‐ray analysis showed that nanocomposites in which layered silicate layers were either delaminated or ordered as in an intercalated structure was obtained. Partially exfoliated structure was observed from TEM photographs of nanocomposites with 3 phr nanoclay. The transport properties, sorption, diffusion, and permeation coefficients were measured using the solvent toluene at 303 K. A higher decrease for the diffusion coefficient for nanocomposites directs the presence of tortuous path for the diffusing molecules. Thermodynamic parameters show a better compatibility for the silicates with rubber resulted in the formation of an elastomeric network. Gas permeability results of the nanocomposites suggest a better barrier resistancefor oxygen molecules even in lower loading of nanoclay and different gas transport models (Nielsen, Bharadwaj, Cussler) were applied to describe the behavior of these nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PP／CaCO3复合材料的力学性能研究

通过采用熔融共混的方法制备了PP／CaCO3复合材料，然后对复合材料的力学性能进行分析，研究了微米级和纳米级CaCO3的表面处理、含量对PP／CaCO3复合材料力学性能的影响规律，并对此影响规律进行合理的解释。     

PP/POE/CaCO3复合材料的性能研究

采用熔融共混工艺制备了聚丙烯/聚烯烃弹性体/碳酸钙(PP/POE/CaCO3)复合材料,研究了POE及CaCO3用量对复合材料力学性能、流变性能及热性能的影响。结果表明:随着POE含量的增加,复合材料的冲击强度显著增大,当POE含量为12%时,冲击强度较纯PP增加233%;同时拉伸强度随POE含量的增加缓慢下降。随着CaCO3含量增加,冲击强度先增加后缓慢下降。     

Enhanced electroactive β phase in three phase PVDF/CaCO3/nanoclay composites: Effect of micro‐CaCO3 and uniaxial stretching

In this study, electroactive polar phase transformation and crystallinity of poly(vinylidene fluoride) (PVDF)‐based composites, such as PVDF/CaCO₃/nanoclay, is explored as a function of micro‐CaCO₃ fraction and draw ratio (R) of uniaxial stretching. Composites including PVDF/clay, PVDF/CaCO₃ and most importantly PVDF/CaCO₃/clay with varying fraction of micro‐CaCO₃ were extruded into homogenous and flexible cast films. Characterization via Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry (DSC) confirmed the presence of β phase in all the composites incorporated with micro‐CaCO₃ and nanoclay either individually (i.e., PVDF/CaCO₃ and PVDF/clay films, respectively) or together (i.e., PVDF/CaCO₃/nanoclay composites). Interestingly, a gradual but significant improvement in this electroactive phase (β phase) was obtained with successive increment in CaCO₃ content into a fixed composition of PVDF and nanoclay (PVDF/CaCO₃/clay composites). Further increment in β phase content was obtained via uniaxial stretching to different draw ratios and at a temperature of 90 °C, where for PVDF/CaCO₃/clay (especially, 100–35‐3 and 100–40‐3) samples almost no α phase was observed irrespective of R. Conversely, the crystallinity of melt extruded samples decreased gradually all the way with CaCO₃ concentration in PVDF/CaCO₃/clay composites compared to the neat PVDF while increased gradually with increasing draw ratio. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44940.     

重钙的处理及其在塑料中的应用

研究了铝酸酯等复合处理剂对重质碳酸钙的活化方法，对制得的活性重质碳酸钙的活化度及石蜡油／碳酸钙混合物的粘度行为进行了表征，拉伸实验结果表明，经过活化处理的重度碳酸钙对LDPE／重质碳酸钙复合材料断裂伸长率的改善特别有效。     

One‐step latex compounding method for producing composites of natural rubber/epoxidized natural rubber/aminosilane‐functionalized montmorillonite: enhancement of tensile strength and oil resistance

Montmorillonite (Mt) was intercalated with cetyltrimethylammonium bromide and functionalized with three types of aminosilane (3‐aminopropyltrimethoxysilane, n‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane and 3‐[2‐(2‐aminoethylamino)ethylamino]propyltrimethoxysilane). The modified Mt was compounded with natural rubber (NR)/epoxidized natural rubber (ENR) via one‐step latex compounding. The effect of the modified Mt content on the oil resistance and mechanical properties of the NR/ENR/modified Mt composites was investigated. The X‐ray diffraction patterns of the composites showed partial intercalation/exfoliation of the modified Mt in the rubber matrix. Cryogenic fracture and X‐ray fluorescence results revealed highly dispersed modified Mt in the composites in the presence of 10 phr ENR. All three aminosilane groups slightly improved the oil resistance, with the long‐alkyl‐length group producing the greatest improvement. The addition of a small amount of modified Mt improved both oil resistance and tensile strength by increasing in the average diffusion path length in the NR matrix and enhancing the interaction between the modified Mt and the epoxide groups in ENR. The addition of 1.0 phr of modified Mt increased the tensile strength by 18% and decreased the elongation at break by 12% compared with a neat NR/ENR blend. © 2017 Society of Chemical Industry     

Modification of rubber powder with peroxide and properties of polypropylene/rubber composites

Waste tire powder was functionalized in the presence of various concentrations of allylamine and benzoyl peroxide. Fourier transform infrared spectroscopy studies confirmed the presence of allylamine on the surface of the rubber powder. The surface energy of the functionalized rubber powder revealed that the introduction of allylamine onto the rubber powder surface increased the surface activity. Improvements in the tensile strength, elongation at break, and storage modulus were observed for polypropylene/modified rubber powder/maleic anhydride grafted polypropylene, and this was attributed to an improvement in the compatibility due to the chemical interaction between the rubber powder and compatibilizer. Evidence for the reaction between the rubber surface and compatibilizer was observed in Fourier transform infrared studies. This peroxide‐initiated monomer‐grafting technique is feasible for large‐scale processes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2237–2243, 2007