马来酸酐接枝聚丙烯增容聚丙烯/碳酸钙复合物力学性能与增容机理

用在50L固相接枝反应器中合成的马来酸酐接枝聚丙烯(PP-g-MAH)作界面改性剂，制备了马来酸酐接枝聚丙烯／聚丙烯／碳酸钙(i-PP／PP-g-MAH／CaCO3)复合材料。研究了i-PP／PP-g-MAH／CaCO3复合材料的力学性能和增容机理。结果表明，PP-g-MAH对i-PP／CaCO3复合物的缺口冲击强度、弯曲强度和拉伸强度均有提高；PP-g-MAH与CaCO3反应形成PP-g-MAH的钙盐，实现反应性增容。     

PP/PP-g-DBM/CaCO_3复合材料的力学性能

以马来酸二丁酯接枝聚丙烯(PP-g-DBM)作界面改性剂,制备了聚丙烯(PP)/PP-g-DBM/CaCO_3复合材料。PP-g-DBM提高了复合材料的抗冲击性能和弹性模量。当w(CaCO_3)为30%时效果最佳,悬臂梁缺口冲击强度达到6 kJ/m~2,相对PP提高了20%;界面改性剂较大程度地改善了分散相(CaCO_3)在连续相(PP)中的分散状态。     

Crystallization of i-PP/CaCO3 Composites and its Correlation with Tensile Properties

Abstract

Investigation of crystallization behaviour of isoatactic polypropylene (i-PP) in i-PP/CaCO₃ composites is carried out through Differential Scanning Calorimetry (DSC) and wide angle X-ray diffraction measurements. The effect of CaCO₃ and its surface treatment with titanate coupling agent on nucleation and growth rate of crystallization, crystallite size distribution and crystallinity, is determined from exothermic crystallization peaks of the composites. The filler concentration dependence of crystallinity determined by both the techniques shows good qualitative agreement. Tensile properties viz. tensile modulus, yield stress and elongation were also measured as functions of filler concentration for both untreated and treated CaCO₃ filled composites. Crystallinity, tensile strength and elongation decreased with increasing filler content in both the cases whereas tensile modulus increased. Crystallization parameters have been correlated with the tensile properties of i-PP/CaCO₃ composites.     

Ultraviolet light aging properties of PVC/CaCO3 composites

The ultraviolet radiation aging behaviors of PVC/CaCO₃ and PVC/CaCO₃/macromolecular modifier composites were studied through whiteness measurement, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscopy, and mechanical properties test. It was found that nano‐CaCO₃ particles used as ultraviolet light screening agents could significantly enhance the antiaging properties of PVC materials. Due to the macromolecular modifier coated on nano‐CaCO₃ particles, the compatibility of nano‐CaCO₃ and PVC matrix was improved, resulting in uniform dispersion of nano‐CaCO₃ in PVC matrix. Therefore, the PVC/CaCO₃/MP composite exhibited better antiaging properties than PVC/CaCO₃ composite. After 12 h of ultraviolet irradiation, the tensile strength retention, elongation at break retention, and impact strength retention of PVC/CaCO₃/MP composite were 79.5%, 74.5%, and 75.3%, which were much higher than that of neat PVC and PVC/CaCO₃ composite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PPS/CaCO3复合材料的结晶行为及动态力学研究

采用DSC、DMA等测试手段研究了PPS/CaCO_3复合材料的结晶行为和动态力学性能。通过对冷结晶峰值温度T_(?)、半结晶时间t_(1/2)、结晶焓△H_c等参数的分析,结果表明:CaCO_3的添加阻碍了PPS分子链的运动,导致了体系结晶速率减小,结晶能力下降,且阻碍作用在CaCO_3含量为3%时最为明显。同时,通过DMA测试,表明CaCO_3的添加使PPS的储能模量和损耗模量都有所增加,其中损耗模量也在CaCO_3含量为3%时达到最大。     

Mechanical Properties of i-PP/AI Composites

Mechanical properties such as tensile, flexural, and impact behavior of Al powder-filled polypropylene composites were studied in the composite composition range 0–10 vol% Al. Tensile strength, modulus, and breaking elongation decreased with increase in filler content due to the formation of weak structure. Analysis of tensile strength data demonstrated the introduction of stress concentration into the structure. Flexural strength and modulus increased with filler content due to increase in rigidity. Izod impact strength at first increased up to a critical Al concentration, beyond which the value decreased.     

Polystyrene/CaCO3 composites with different CaCO3 radius and different nano‐CaCO3 content—structure and properties

The Archimedes' principle and physical theory are attempted to analysis the densification and structure of the polystyrene (PS) composites by melt compounding with CaCO₃ having different particle size. The difference between the measured specific volume (ν) andthe theoretically calculated specific volume (ν_mix), Δν = ν−ν_mix, can reflect the densification of the composites. It is clearly demonstrated that the PS composites become more condensed with the reduction of the CaCO₃ particle size. Especially, when the content for nano‐CaCO₃ achieves 2 wt%, the Δν value of the composites reaches the least, which shows the best densification. Meanwhile, the glass transition temperature (T_g) reaches the maximum value of about 100°C by differential scanning calorimetry (DSC) and thermal mechanical analysis (TMA), which indirectly reveals the composites microstructure more condensed. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveal that 2 wt% nano‐CaCO₃ uniformly disperses in PS composites. The CaCO₃ selected in this experiment has certain toughening effect on PS. The impact and tensile strength increase with addition of nano‐CaCO₃, but the elongation at break decreases. When nano‐CaCO₃ content achieved 2 wt%, the impact and tensile strength present the maximum value of 1.63 KJ/m² and 44.5 MPa, which is higher than the pure PS and the composites filled with the same content of micro‐CaCO₃. POLYM. COMPOS., 31:1258–1264, 2010. © 2009 Society of Plastics Engineers     

The synthesis of vaterite and physical properties of PP/CaCO3 composites

Vaterite was synthesized in the emulsion state at 50 ‡C. The mixing method was found to have a significant effect on the shape of vaterite. In order to investigate the effect of CaCO₃ morphology on mechanical property and thermal property of polypropylene, cubic forms of calcite and needle forms of aragonite were also prepared in the emulsion states. When vaterite was used as a filler in the PP/CaCO₃ composites, the crystallization temperature and crystallinity were higher than those with other forms. In addition, the size of spherullite of polypropylene was the finest when vaterite was used. Therefore, the vaterite is considered as a proper nucleating agent for polypropylene.     

PP/针形纳米CaCO3复合材料的力学性能

用硬脂酸皂化改性针形纳米CaCO3表面后,将其与聚丙烯(PP)共混、挤出和注塑,制成PP／CaCO3纳米复合材料。与纯PP相比,填充针形纳米CaCO3的体积分数为4.21％时,PP体系的冲击强度和断裂伸长率分别提高了49％,339％,拉伸强度下降2．7％。改性后的纳米CaCO3与PP之间的界面作用与改性前相比有所减弱,冲击断面扫描电子显微镜照片显示,针形纳米CaCO3均匀地分散在PP基体中。偏光显微照片显示,针形纳米CaCO3对PP有明显的异相成核作用。     

天然橡胶/改性纳米碳酸钙复合材料的形态与力学性能

比较了3种改性纳米碳酸钙,如硬脂酸改性的纳米碳酸钙(CCR)、CCR的固相改性纳米碳酸钙(M—CCR)、悬浮改性纳米碳酸钙(M—CaCO3)与天然橡胶组成的复合材料硫化胶的力学性能和形态。结果表明,3种复合材料的硫化胶与天然橡胶硫化胶相比,其力学性能得到了明显改善,其中含有M—CaCO3的复合材料力学性能的提高和形态的改善优于含有CCR和M—CCR者。     

纳米CaCO_3含量对PP/SBS/CaCO_3复合材料力学性能的影响

通过双螺杆共混方法制备聚丙烯(PP)/苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)/Ca-CO3复合材料,并采用扫描电镜(SEM)、力学性能测试和偏光显微镜研究了纳米CaCO3用量对该复合体系微观结构、力学性能以及结晶形貌的影响。结果表明:纳米CaCO3粒子在PP中均匀地分散可细化晶粒并起到了增韧增强的效果。当加入纳米CaCO3的质量分数为2%时,其综合性能最好。     

Morphology and mechanical properties of PP/POE/nano‐CaCO3 composites

The mechanical properties including tensile, flexural, and impact of the nanometer on calcium carbonate (nano‐CaCO₃) filled polypropylene (PP)/poly (ethylene‐co‐octene) (POE) composites were measured at room temperature to identify the effects of the POE content on the mechanical properties. It was found that the Young's modulus, tensile strength, and tensile elongation at break decreased nonlinearly while the tensile fracture strength varied slightly with increasing the POE weight fraction; the V‐notched and unnotched Izod impact fracture strength increased nonlinearly with an increase of the POE weight fraction; the flexural modulus and strength decreased roughly linearly with increasing the POE weight fraction. Furthermore, the impact fracture surface of the specimens was observed by means of a scanning electronic microscope to discuss the toughening mechanisms. POLYM. COMPOS., 37:539–546, 2016. © 2014 Society of Plastics Engineers     

Bio-based compatibiliser enhancing the interface properties of CaCO3/recycled high-density polyethylene composites

The fabrication of composites of two or more materials with different polarities requires the use of compatibilisers to improve interface properties. However, most compatibilisers used for industrial production are derived from the cracking products of petroleum, which is a limited resource susceptible to price fluctuations and pollutes the environment. In this study, a new compatibiliser derived from renewable plant-oil-based products, ESO–G–OA, was designed and synthesized using epoxy soybean oil, oleic acid, and glycerol. Scanning electron microscopy results showed that ESO–G–OA can effectively improve the dispersion of CaCO₃ in a recycled high-density polyethylene (reHDPE) matrix and reduce the interfacial gap between the two phases. The analysis of the mechanical properties showed that the ESO–G–OA-modified composite has higher tensile and impact strength than unmodified samples. The ESO–G–OA modification improved the thermal stability and melt flow of the composite and reduced the energy consumption during processing. Moreover, the excellent compatibility of ESO–G–OA can improve the comprehensive properties of CaCO₃/reHDPE composites, compensating for the performance reduction caused by the multiple processing steps necessary to obtain reHDPE. This confirmed that ESO–G–OA has promising application prospects in the production of composites requiring compatibilisers.     

Mechanical Properties of Impact i-PP/CSM Rubber Blends

ABSTRACT

The impact strength and the tensile behavior of an impact grade of isotactic polypropylene (impact i-pp)/chlorosulfonated polyethylene (CSM) rubber blends are studied at the CSM rubber concentrations 0 to 23.4 vol%. The impact strength, which increased with CSM rubber concentration, has been analyzed on the basis of the interphase adhesion and crazing mechanisms. Tensile modulus and strength decreased whereas breaking elongation increased with increase in CSM rubber content. Predictive models have been used to explain the tensile modulus and strength properties. Scanning electron microscopy has been employed to study the phase structure.     

Plasticization of nano‐CaCO3 in polystyrene/nano‐CaCO3 composites

The shear rheological properties of polystyrene (PS)/nano‐CaCO₃ composites were studied to determine the plasticization of nano‐CaCO₃ to PS. The composites were prepared by melt extrusion. A poly(styrene–butadiene–styrene) triblock copolymer (SBS), a poly(styrene–isoprene–styrene) triblock copolymer (SIS), SBS‐grafted maleic anhydride (SBS–MAH), and SIS‐grafted maleic anhydride were used as modifiers or compatibilizers. Because of the weak interaction between CaCO₃ and the PS matrix, the composites with 1 and 3 phr CaCO₃ loadings exhibited apparently higher melt shear rates under the same shear stress with respect to the matrix polymer. The storage moduli for the composites increased with low CaCO₃ concentrations. The results showed that CaCO₃ had some effects on the compatibility of PS/SBS (or SBS–MAH)/CaCO₃ composites, in which SBS could effectively retard the movement of PS chain segments. The improvement of compatibility, due to the chemical interaction between CaCO₃ and the grafted maleic anhydride, had obvious effects on the rheological behavior of the composites, the melt shear rate of the composites decreased greatly, and the results showed that nano‐CaCO₃ could plasticize the PS matrix to some extent. Rheological methods provided an indirect but useful characterization of the composite structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Mechanical behavior of CaCO3 particulate-filled β-crystalline phase polypropylene composites

β-crystalline phase polypropylene (PP) composites containing 5, 10, 20, 30, and 40% (by weight) of CaCO₃ filler were prepared by injection molding. The β-form PP was produced by adding a bicomponent β-nucleator consisting of equal amounts of pimelic acid and calcium stearate. The morphology, static tensile, and impact properties of these composites were investigated in this study. Scanning electron microscopy (SEM) observations revealed that the β-spherulites of the polymer matrix of the composites exhibit curved lamellae and sheaf-like structures. The fillers were observed to disperse within the inter-lamellar spacings of the β-PP composite containing 10% calcium carbonate addition. However, the filler particles tend to link together to form larger aggregates when the filler content reaches 20%. Static tensile measurements showed that the elastic modulus of the composites increases with increasing filler content but the yield strength decreases with increasing filler addition. The falling weight Charpy impact test indicated that the β-PP polymer exhibits the highest critical strain energy release rate (G_c) value. However, there was a drastic drop in G_c of the β-PP composites with increasing filler content. The results are discussed and explained in terms of materials morphology.     

Influence of strain rate on the toughening effect of CaCO3 in polypropylene/CaCO3 composites

The effects of 40 and 50 wt% of calcium carbonate on the mechanical properties of polypropylene were investigated by uniaxial tensile deformation at room temperature and at loading rates of 5, 50, and 125 mm/min. The results showed that the addition of calcium carbonate to polypropylene decreased yield strength while increasing modulus. The decreases yield strength was attributed to the poor adhesion between filler and matrix. The tensile toughness of polypropylene was improved by the addition of calcium carbonate particles at constant strain rate because of the plastic deformation of interparticle ligaments following particle‐matrix debonding. The (strain rate) sensitive behavior of the composites (at constant calcium carbonate content) was observed. J. VINYL ADDIT. TECHNOL., 19:271–275, 2013. © 2013 Society of Plastics Engineers     

Mechanical Properties of Talc Filled i-PP/CSM Rubber Composites

ABSTRACT

Tensile and impact properties of talc-filled i-PP/CSM rubber (20 phr, 0.13 vol fraction) blends were studied in the talc concentration range 0–0.149 vol fraction (0–50 phr). The tensile modulus increased whereas the tensile breaking strength and the strain-at-break decreased with increase in the talc concentration. The modulus increase and the strain decrease were due to enhanced mechanical restraint imposed by the talc particles on the polymer blend decreasing its deformability. Formation of stress concentration points explained the decrease in the tensile strength. The Izod impact strength showed a significant decrease with increase in the filler content. Surface treatment of the talc particles with a titanate coupling agent LICA 12 increased the wetting of the talc by the polymer blend, further modifying the strength properties. Scanning electron microscopic studies showed enhanced dispersion of the filler particles sequential to the surface treatment, effecting modifications of the composite strength properties.     

PPR/甘蔗渣复合材料的力学性能

利用硅烷处理的甘蔗渣纤维填充无规共聚聚丙烯制备了复合材料,研究其力学性能与相态结构。结果表明:在甘蔗渣用量为10～15份时,用硅烷KH570处理的甘蔗渣制备的复合材料较直接填充物的拉伸强度与冲击强度各提高30％以上;试样结晶更完善,纤维在树脂中分布更均匀。     

填料表面处理对ABS/CaCO3复合材料性能的影响

在室温下,测定了CaCO3填充丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)复合材料的力学性能。结果表明,随着CaCO3质量分数[W(CaCO3)]的增加,试样的拉伸弹性模量呈非线性提高,而拉伸强度和拉伸断裂能下降。当ω(CaCO3)小于10％时,试样的简支梁缺口冲击强度随着ω(CaCO3)的增加而迅速减小,而弯曲强度却增大,ω(CaCO3)达10％后两者均缓慢地减小。CaCO3的表面处理及其粒径大小对上述力学性能的影响不太明显。此外,测量了试样的维卡软化温度(TVC）,TVC随着ω(CaCO3)的增加而提高,这表明填充CaCO3粒子有利于改善ABS的耐热性能。