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     

Fracture behavior of PVC/Blendex/nano‐CaCO3 composites

PVC/Blendex/Nano‐CaCO₃ composites were prepared by melt‐blending method. The Blendex (BLENDEX® 338) (GE Specialty Chemicals Co., Ltd., Shanghai, China) was an acrylonitrile‐butadiene‐styrene copolymer with high butadiene content. The fracture behavior of PVC/Blendex/nano‐CaCO₃ composites was studied using a modified essential work of fracture model, U/A = u₀ + u_dl, where u₀ is the limiting specific fracture energy and u_d is the dissipative energy density. The u₀ of PVC/Blendex blend could be greatly increased by the addition of nano‐CaCO₃, while the u_d was decreased. Nano‐CaCO₃ with particle size of 38 nm increased the u₀ of PVC/Blendex blend more effectively than that with particle size of 64 nm, when nano‐CaCO₃ content was below 10 phr. Both the u₀ and u_d of PVC/Blendex/nano‐CaCO₃ composites were not much affected by increasing specimen thickness from 3 mm to 5 mm, while the two fracture parameters were increased with increasing loading rate from 2 mm/min to 10 mm/min, and u_d was found to be more sensitive to the loading rate than u₀. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 953–961, 2005     

CaCO3／PVC纳米复合材料的研究

研究了经过表面改性的纳米CaCO3添加量对PVC／米CaCO3复合材料聚合工艺和力学性能的影响。结果表明,纳米CaCO3经过处理后,表面包覆了一薄层的有机物。纳米CaCO3在3％-7％的添加范围内,可以缩短聚合反应时间。纳米PVC与普通PVC比较,冲击强度可提高到9．38kJ／m^2,断裂伸长率在拉伸强度略有降低的前提下增大到60．2％。纳米CaCO3的添加量为7％时,可以得到综合性能较好的纳米CaCO3／PVC复合树脂。     

PVC/CaCO3复合材料的结构与性能研究

研究了表面改性微米重质CaCO3填充的聚氯乙烯（PVC）树脂所得PVC／CaCO3复合材料的结构和热力学与机械性能。结果表明，改性微米重质CaCO3的填充能明显提高PVC基复合材料的缺口冲击强度和维卡软化温度。当填充质量分数20％的改性微米重质CaCO3后，PVC／CaCO3复合材料的冲击强度为20．92kJ／m^2，比未加微米重质CaCO3的提高了49．9％。扫描电镜（SEM）观察复合材料的表面形态，发现拉伸断面有拉丝现象。热失重-差示扫描量热分析发现，微米重质CaCO3对PVC基复合材料分解有一定的抑制作用。     

MBS/CaCO3协同增韧PVC的性能研究

分别研究了1 250目、2 500目CaCO3以及甲基丙烯酸-丁二烯-苯乙烯共聚物(MBS)对聚氯乙烯(PVC)力学性能的影响;并且选用15%MBS与1 250目CaCO3复配制备出了高韧性的PVC材料。结果表明:MBS能有效提高PVC的冲击强度;1 250目CaCO3与2 500目CaCO3相比,更易于分散,增韧的效果更好;MBS与1 250目CaCO3协同增韧,使PVC冲击强度达120 kJ/m2,拉伸强度约为37 MPa,断裂伸长率在40%左右。     

接触角法研究PVC/包覆CaCO3复合材料性能

在常温下,测定了几种已知表面张力参数的液体与聚氯乙烯（PVC）/包覆CaCO3复合体系间的接触角,计算了粘合功、Harkins铺展系数,结果表明：随着上述两参数的增加,CaCO3颗粒更容易在PVC基体中分散：Molar实验和扫描电子显微镜观察冲击断面,证实了热力学计算结果。     

Accelerated ultraviolet weathering of PVC/wood‐flour composites

Ultraviolet weathering performance of polyvinyl chloride (PVC) filled with different concentrations of wood flour was studied. Extruded PVC/wood‐flour composite samples were subjected to cyclic ultraviolet lamps/condensation exposures and assessed over a total of 400 and 2600 hours. Each assessment consisted of DRIFTFTIR and XPS collections, contact angle measurement, color measurement, and tensile property testing. The experimental results indicated that wood flours are effective chromophore materials since their incorporation into a rigid PVC matrix accelerated the degradation of the polymeric matrix. Photodegradation converted unfilled PVC samples to a colored material of lower extensibility. Although composite samples exhibited greater discoloration than unfilled PVC samples, they retained all their original strength and stiffness properties even after 2600 hours of cyclic UV irradiation/condensation exposures.     

Microporous polypropylene sheets containing CaCO3 filler: Effects of stretching ratio and removing CaCO3 filler

Microporous polypropylene sheets are prepared by biaxially stretching polypropylene sheets containing CaCO₃ filler. Here, the stretching ratio is one of the most important factors in the preparative process, and removing the CaCO₃ filler also affects the sheet properties. Their effects were studied in relation to the properties and the structure of the microporous polypropylene sheets. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1543–1553, 1998     

PVC/改性纳米CaCO3复合材料的制备及性能

合成了纳米CaCO3表面改性剂AP-01,将此改性剂改性的纳米CaCO3用于硬质聚氯乙烯(PVC)抗冲改性.观察PVC/改性纳米CaCO3复合材料的微观结构,并测试其力学性能.结果表明:改性纳米CaCO3以海岛结构分散于PVC基体中.改性纳米CaCO3加入量在10%时,复合材料缺口冲击强度达到18.2 kJ/m2,而复合材料拉伸强度几乎没有改变.对比普通硬脂酸改性纳米CaCO3增韧PVC,其具有明显的性能优势.     

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     

CaCO3对UPR浇铸体拉伸性能的影响

研究了CaCO3填料对不饱和聚酯树脂（UPR）浇铸体拉伸强度的影响，借助于应变片电测技术研究了CaCO3填料对树脂浇铸体的拉伸变形特性和弹性模量的作用。结果表明：在所毒取的实验条件下，填料CaCO3的添加量对UPR的拉伸强度和弹性模量有显著的影响，添加量为8％（质量分数）时试样的强度比纯树脂提高了大约54％，分析了填料CaCO3提高UPR拉伸强度的原因在于其显著提高了材料的韧性。     

PVC/CaCO3纳米复合材料结构与性能的研究

研究了PVC／CaCO3纳米复合材料的力学性能和热性能,观察了复合材料冲击缺口的断面微观形态和纳米CaCO3粒子在PVC中的分散情况。结果表明：当纳米CaCO3粒子的质量分数为10％时,PVC／CaCO3纳米复合材料的冲击强度提高了约365％,拉伸强度略有提高;当纳米CaCO3质量分数超过10％以后,纳米粒子在基体中的分散情况变差;随着纳米CaO3用量的增加,PVC／CaCO3纳米复合材料的玻璃化转变温度先降后升。     

PVC的微发泡处理及PVC/CaCO3的原位复合

研究了用原位生成法制备PVC/纳米CaCO3复合母粒的过程. 首先利用混合溶剂将PVC粉料溶胀,同时带入发泡剂偶氮二异丁腈,在112oC下进行固相微发泡. 利用已发泡的PVC,采用原位生成法制备了纳米CaCO3/PVC复合母粒. 通过扫描电镜观察,发现已发泡PVC颗粒表面布满微孔,纳米级CaCO3填充在PVC孔洞里. PVC/纳米CaCO3复合母粒同时起到了增韧增强的作用.     

CaCO3 as a new member of high solar-reflective filler on the cooling property in polymer composites

Calcium carbonate (CaCO₃) is the most commonly used inorganic filler in polymer materials to improve the mechanical properties and reduce the costs. However, there are few reports on the preparation of cooling materials using CaCO₃. In this study, CaCO₃ was introduced into the polymer matrix as a solar reflective filler to prepare passive cooling materials. Specifically, the influences of CaCO₃ content on the structure and performances of polyvinyl chloride (PVC)/CaCO₃ composite films were characterized by scanning electron microscope (SEM), contact angle test, surface roughness and glossiness, solar reflectivity, thermal emissivity, temperature test and mechanical property characterization. When the volume fraction of CaCO₃ reaches 67%, the total solar reflectance of PVC/CaCO₃ composite films is 80.8%, which is 351.4% higher than that of PVC films. CaCO₃ powder has little influence on the thermal emissivity of the atmospheric window (3-5 μm and 8-13 μm) of the composite films, which remains at a high level about 0.86. In temperature test, the final temperature of sample 67 v% is only 26.8°C, which is only 2.8°C higher than the room temperature and 22.2°C lower than that of PVC films. For comparison, the cooling performance of PVC/titanium dioxide (TiO₂) composite films with 10 v% TiO₂ was also measured, and the final temperature is 29.1°C, even 2.3°C higher than that of PVC/CaCO₃ composite films with 67 v% CaCO₃. In this study, the cost-effective and solar-reflective PVC/CaCO₃ composites have potential application in cooling material field.     

CaCO_3/NR复合材料制备工艺的研究

采用CaO、CO2和天然胶乳等为原料,将CaCO3的制备工艺和NR的制备工艺相结合,先将Ca（OH）2与CO2反应制备CaCO3乳液再与天然胶乳共混、共凝制备CaCO3/NR复合材料。采用正交实验方法,探讨了Ca（OH）2用量、炭化温度、成核剂（Na5P3O10）和分散剂（EDTA）的用量对CaCO3/NR复合材料性能的影响,获得制备CaCO3/NR复合材料的最佳工艺。结果表明CaCO3/NR复合材料的适宜制备工艺条件为：Ca（OH）2质量分数为7.5%,碳化温度为20℃,晶形控制剂质量分数为0.60%,分散剂质量分数为0.65%。     

Mechanical properties of i-PP/CaCO3 composites

Tensile and impact behavior of CaCO₃-filled polypropylene was studied in the composition range 0–60 wt % filler. Tensile modulus increased while tensile strength and breaking elongation decreased with increase in CaCO₃ content. The modulus increase and elongation decrease were attributed to increased filler–polymer interaction resulting in reduction in molecular mobility, while increased amorphization and obstruction to stress transfer accounted for the tensile strength decrease. Analysis of tensile strength data showed introduction of stress concentration in the composites. Izod impact strength at first increased up to a critical CaCO₃ content, beyond which the value decreased. Surface treatment of CaCO₃ with a titanate coupling agent LICA 12 enhances the adhesion of the filler and polymer, which further modifies the strength properties. Scanning electron microscopic studies indicated better dispersion of CaCO₃ particles upon surface treatment, which effected the changes in the strength properties of the composites.     

稀土稳定剂对PVC/CaCO3复合体系影响的研究

测试并分析了稀土稳定剂对PVC/CaCO3复合材料的静态稳定时间、流变性能及力学性能的影响,并与复合铅稳定剂进行了对比实验。结果表明:稀土稳定剂在复合材料中表现出较好的热稳定性、加工性和增容偶联的功效;在相同的配比条件下,稀土稳定体系的拉伸强度和冲击韧性比复合铅稳定体系的高。复合材料试样的断面SEM照片显示CaCO3在稀土稳定体系中粒子分散均匀,进一步验证了稀土稳定剂有增容偶联的作用。     

碳酸钙和滑石粉对PVC/ABS合金性能的研究

研究了无机填料粒状碳酸钙(CaCO3)和片状滑石粉(Talc)对聚氯乙烯(PVC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)合金的力学性能、维卡软化温度和加工性能的影响,SEM观察PVC/ABS合金的冲击断面微观形貌和无机填料的分散情况。结果表明,CaCO3和Talc复配可以改善PVC/ABS合金的冲击性能和拉伸性能;Talc可以大幅度的提高PVC/ABS合金维卡软化温度;CaCO3和Talc复配不利于PVC/ABS合金维卡软化温度和加工性能的提高。     

PVC/高分子表面修饰CaCO3复合材料的加工性能研究

采用液态高分子改性剂对CaCO3进行包覆改性,得到高分子表面修饰CaCO3(CLCC)。使用转矩流变仪、紫外可见分光光度计及白度测定仪对聚氯乙烯(PVC)/CaCO3复合材料和PVC/CLCC复合材料的加工性能进行了研究。结果表明,CLCC颗粒的加入可以缩短PVC的塑化时间,改善其加工性能,提高PVC生产效率;而抑制了PVC在熔融加工过程中的降解;PVC/CLCC复合材料的白度保持率高于PVC/CaCO3复合材料。     

聚合物包覆对纳米CaCO3在PVC中分散的影响

以偶联改性纳米CaCO3和甲基丙烯酸甲酯（MMA）为原料,原位乳液聚合制得PMMA接枝包覆纳米CaCO3,以其与PVC熔融共混制备复合材料,研究了纳米CaCO3在共混体中的分散和与PVC界面的结合.与未改性纳米CaCO3相比,纳米CaCO3接枝包覆PMMA后,在PVC中的分散性能得到明显改善,粒子被分散得更加细小、均匀.PMMA接枝包覆纳米CaCO3与PVC界面间相容性能最好,比小分子改性CaCO3与PVC间的黏结作用更强.采用PMMA包覆纳米CaCO3粒子改性PVC,比未改性纳米CaCO3改性PVC有更好的冲击性能及拉伸性能.