纳米复合树脂口腔修复材料的研制及性能表征

利用纳米技术和分子组装技术,将具有生物相容性的羟基磷灰石材料作为牙齿龋洞的修复充填的无机填料,与有机树脂基质有机地复合和组装,从而开发出强度高、易加工且具有良好生物相容性的复合树脂牙齿修复材料。根据我国医药行业标准YY1042—2003《牙科学聚合物基充填、修复和粘固材料》,对纳米复合树脂材料挠曲强度、压缩强度以及吸水值等性能进行了实验室阶段的表征,性能完全达到目前临床使用的进口牙科复合树脂的各项指标。     

牙科复合树脂中无机填料的研究进展

牙科复合树脂是一类由有机树脂基质和经过表面处理的无机填料及引发系统组合而成的牙科修复材料。无机填料作为复合树脂的分散相,在牙科复合树脂中具有重要作用,对复合树脂的力学性能、物理性能、化学性能都有着重要的影响。介绍了无机填料的种类、形态、含量、粒径大小及其表面处理,并结合许多学者对复合树脂中无机填料的研究,探讨无机填料对复合树脂性能的影响,最后展望了复合树脂应提高的性能和无机填料努力的方向。     

AlCrN硬质涂层材料的研究进展

综述了AlCrN涂层、以AlCrN为基的多元涂层和纳米技术涂层的研究现状,侧重描述了其结构、热稳定性、抗腐蚀性和机械加工性能,并重点介绍了Al在涂层中的作用及影响.研究表明:在AlCrN涂层中添加某些合金元素可进一步提高其综合性能;应用纳米技术形成的纳米多层结构和纳米复合结构也能促进AlCrN涂层性能的提高.对AlCrN涂层进行多元化以及纳米技术的应用是该涂层材料今后的发展方向.     

SA-g-P(AA-co-AMPS)/KL对罗丹明6G的吸附性能研究

研究了海藻酸钠接枝聚丙烯酸2-丙烯酰胺-2-甲基丙磺酸/高岭土(SA-g-P(AA-co-AMPS)/KL)复合树脂对罗丹明6G染液的吸附性能。探讨了染料初始浓度、吸附时间、pH值对吸附性能的影响,并对吸附结果进行热力学和动力学拟合。结果表明,复合树脂对罗丹明6G在实验条件下的最大吸附量为710 mg/g,吸附过程是自发的,且同时符合Freudlich方程和Redlich-Peterson方程,动力学符合拟二级动力学方程。     

镁铝双金属氧化物复合丙烯酸酯系吸油树脂的合成及吸附性能研究

以硝酸镁、硝酸铝和尿素为原料,并加入十二烷基磺酸钠制备了疏水性镁铝氧化物。以丙烯酸丁酯(BA)、甲基丙烯酸丁酯(BMA)和苯乙烯(St)为单体,聚乙烯醇(PVA)为分散剂,乙酸乙酯为致孔剂,过氧化苯甲酰(BPO)为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,加入一定量疏水性镁铝氧化物,合成镁铝双金属氧化物复合丙烯酸酯系吸油树脂,并对该复合树脂的吸油性能进行了性能测试。结果表明,复合树脂对四氯化碳、三氯甲烷和甲苯的最高吸附倍率分别为42.89、36.29、26.85g/g。对复合树脂吸附四氯化碳的动力学模型拟合结果表明,复合树脂吸油符合准一级动力学模型。复合树脂的热重分析结果表明,复合树脂比原树脂的热稳定性有一定提高。     

红外差示光谱法在复合材料界面反应研究中的应用

本文以红外差示光谱法从化学键的角度对偶联剂与几种复合树脂常用填料的相互作用以及树脂基体间的相互作用予以探讨,为复合树脂的制备中如何选择填料以获得强度高、性能好的牙科材料提供了研究方法和理论依据。     

光聚合法高岭土复合AA-AM-SSS高吸水性树脂的研究

以N,N-亚甲基双丙烯酰胺为交联剂,1173为光引发剂,采用紫外光引发聚合的方法制备了高岭土/聚(丙烯酸-丙烯酰胺-苯乙烯磺酸钠)(AA-AM-SSS)高吸水性复合树脂。研究了苯乙烯磺酸钠、高岭土含量、交联剂用量和引发剂用量等对复合树脂的吸水率的影响,并用FT-IR和SEM等表征了复合树脂的结构,用TGA和DSC表征了复合树脂的耐热性。结果表明:引发剂、交联剂和高岭土用量影响高岭土复合树脂的吸水率和保水率。当苯乙烯磺酸钠的质量分数为10%,高岭土的质量分数为10%时,高岭土复合树脂具有较好的性能,平衡吸水率为540g/g。SEM结果表明,高岭土呈颗粒状不规则地分布于树脂中,树脂的表面有许多微小的圆孔。     

三级硅基填料的构筑及其对牙科复合树脂性能的影响

为提高无机填料在牙科复合树脂中的堆积密度,采用八乙烯基多面体低聚倍半硅氧烷(OV-POSS)作为第三级填料,填充双模SiO_2填料(SiO_2纳米粒子SiO_2纳米团簇)型复合树脂中的空隙。用高分辨率透射电镜(HR-TEM)和动态光散射仪(DLS),研究了OV-POSS的形貌和粒径,并利用UV-vis-NIR分光光度计、万能实验机和MTT比色法,研究了三级填料的组成对复合树脂性能的影响。结果表明:OV-POSS形貌为近球形,粒径为(4.0±2.9)nm;当OV-POSS的添加量≤5wt.%时,复合树脂的性能逐渐得到改善,尤其当OV-POSS的质量分数为5%时,复合树脂的透光率和细胞活性优于商品化纳米团簇型树脂Z350 XT,且其弯曲强度(112.3 MPa±5.6 MPa)、弯曲模量(6.6 GPa±0.2 GPa)和压缩强度(217.8 MPa±5.3 MPa)达到最大值,较未添加OV-POSS的树脂分别提高了7.2%、4.8%和5.8%。但是,随着OV-POSS含量增加(≥10wt.%),OV-POSS易聚集且散射更多的光,导致复合树脂性能下降。     

红外差示光谱法在复合材料界面反应研究中的应用

本文以红外差示光谱法从化学键的角度对偶联剂与几种复合树脂常用填料的相互作用以及树脂基体间的相互作用予以探讨,为复合树脂的制备中如何选择填料以获得强度高、性能好的牙科材料提供了研究方法和理论依据。      

退役绝缘子芯棒粉末在电缆沟盖板中的应用

回收退役的聚合物绝缘子成为一个日益迫切的环境和经济问题。将退役绝缘子芯棒粉末粉碎,作为填料添加入玻璃纤维增强环氧树脂复合树脂盖板中,通过高温模压固化,制备了退役绝缘子芯棒粉末掺杂复合树脂电缆沟盖板。通过抗冲击韧性试验仪、热变形维卡温度测量仪和电子万能试验机对制备的退役绝缘子芯棒粉末掺杂复合树脂电缆沟盖板进行了力学性能及热学性能测试。结果表明:相关性能数据结果均高于普通混凝土盖板及钢纤维增强混凝土盖板。本实验在不影响复合树脂盖板各方面性能的条件下达到了回收利用大量退役芯棒的效果,在废旧高分子材料回收利用、节约能源、材料可持续发展方面具有重要意义。     

Effect of alumina,silk and ceria short fibers in reinforcement of Bis-GMA/TEGDMA dental resin

The present study is focused to investigate influence of short fibers such as Alumina Microfibers (AMFs), Silk Microfibers (SMFs) and Ceria Nanofibers (CNFs) as reinforcements in Bis-GMA/TEGDMA resin towards development of composite dental filler. Morphologies of AMFs, SMFs, CNFs and their representative fracture surfaces of the reinforced dental resins/composites were examined by SEM. X-ray Diffraction Analysis was done to analyse the phase of the fibers used in this study and degree-of-conversion of the fiber incorporated base resin was studied by FTIR. Viscosity study of fiber resin mixture, depth of cure and mass change behaviour of the fibers resin composites in artificial saliva were done to analyse the flow ability and physical properties of the fiber resin composites. Mechanical properties of the composites were tested by a universal testing machine. This study demonstrated that incorporation of 10% AMFs, 5% SMFs, and 3.33% CNFs individually in Bis-GMA/TEGDMA dental resin resulted in similar degree of conversion compared to the control. Also the fiber reinforced composites (10% AMFs, 5% SMFs, and 3.33% CNFs) demonstrated significant improvement in mechanical properties compared to Bis-GMA/TEGDMA resin (Control). However, depth of cure was significantly reduced due to incorporation of fibers in the resin. The reinforcement effect of AMFs, SMFs in dental resin was superior due to their uniform distribution and good interfacial bonding between fibers and resin matrix. In case of CNFs, rapid increase in viscosity during mixing of fibers with resin and inhomogeneous mixing were the major problem encountered during formulation, which was mainly associated with high surface to volume ration of the nanofibers. The resultant composite containing CNFs had less improvement in mechanical properties which may be due to less fiber content, formation of agglomerates and improper distribution of the fibers in the composite which subsequently resulted in reduction of adhesive strength.     

牙科复合树脂中无机填料的堆积孔隙率与其粒度分布的关系

通过测定松装密度和振实密度 ,研究了牙科复合树脂中无机填料的粒度分布与其堆积孔隙率之间的关系。使用Mathematica软件和SAS/STAT软件 ,用非线性回归的方法得到了无机填料的粒度分布与其堆积密度之间关系的经验公式 ,结论为无机填料 (BG)的平均粒径为 1μm ,可以作为影响堆积优化的判据     

Molecular dynamics simulation of a novel kind of polymer composite incorporated with polyhedral oligomeric silsesquioxane (POSS)

Molecular dynamics (MD) simulation is adopted to investigate the physical properties of a novel dental nano-composite resin with poly-functional polyhedral oligomeric silsesquioxane (POSS). An improved method is proposed to model the cross-link polymer. The quality of the proposed technique is verified by wide X-ray scattering (WXRS) and volume–temperature behavior. The excellent agreement proves the accuracy of the models and the force field. Mechanical properties and volume shrinkage of various POSS weight-percentage resins are predicted, and the results are also compared with available experimental data. Further analysis provides some molecular insight about the effect of POSS on the dental composite resin. The improved method could be employed in further research of new cross-link dental materials with complex structures.     

深潜浮力材料的结构分析与设计

本文详细分析了空心微球填充的树脂类材料的结构,讨论了轻质填充物（空心微球）的结构与力学性能,计算分析了空心微球的结构与性能对复合材料性能的影响。以普通玻璃微珠填充的环氧树脂材料为例,分析了玻璃微球填充的最大比例与可能得到的浮力材料的最高性能。总结了浮力材料的设计原则和和发展方向。     

HPLC analysis of components released from dental composites with different resin compositions using different extraction media

Components released from dental composite resins are essential factors in the assessment of biocompatibility of these materials. The effect of different extraction media on monomer release from composite resins based on different monomer types was evaluated. Three types of visible light cured composite resins were formulated based on the following monomers: triethylene glycol dimethacrylate (TEGDMA), bisphenol A glycerolate dimethacrylate (BisGMA), and urethane dimethacrylate (UDMA). Seventy-five composite resin discs were fabricated and light cured for 1 min in the absence of oxygen. Extraction media used were: distilled water, saline solution, artificial saliva, serum-free culture medium, and culture medium with 10% fetal calf serum. The analysis of extracts from the composite resins was carried out by High Performance Liquid Chromatography (HPLC). Quantifiable amounts of TEGDMA were released into the aqueous media. However, BisGMA and UDMA were not detectable in any of the extracts from the composite resins. Statistical analysis by one-way ANOVA followed by Tukey’s test showed that there was a significant difference in TEGDMA release between culture media and other media (p < 0.05). From the results of this experiment it can be concluded that TEGDMA-based composite resins can release a high quantity of monomer into aqueous environments. The type of extraction medium may have a significant effect on monomer release from composite resins.     

Fracture and Tribological Evaluation of Dental Composite Resins Containing Pre-polymerized Particle Fillers

The fracture and tribological evaluation of dental composite resin containing pre-polymerized particle fillers were investigated. Composite resins, e.g. metafil, silux plus, heliomolar and palfique estelite were selected as specimens in order to evaluate the effects of pre-polymerized particle filler on the fracture and wear characteristics of composite resins. In the wear tests, a ball-on-flat wear test method was used. The friction coefficient of metafil was quite high.The wear resistance of silux plus and palfique estelite was better than that of metafil and heliomolar under the same experimental condition. The main wear mechanism of composite resins containing pre-polymerized particle fillers was an abrasive wear by brittle fracture of pre-polymerized particles and by debonding of fillers and matrix.     

Trends in nanotechnology patents applied to the health sector

The aim of the article is to present a method for identifying trends in patent applications for nanotechnology applied to the health sector around the world, based on the International Patent Classification. This classification divides the sector into: dental care, drugs, diagnostic kits, and medical apparatus & medical care. The Derwent database was mined for patent documents using nanotechnology terms associated with the IPC subclasses from the health subsectors. The number of patents was found to be rising, led by the United States, particularly universities and R centers. In the dental care subsector, nanotechnology was found to be used in composite material for manufacturing dental appliances. In drugs, the focus is on the use of nanoparticulate compositions comprising agents that are useful for a variety of diseases. In diagnostic kits, nanostructures have been patented that are capable of detecting target analytes. Meanwhile, in medical apparatus & medical care, patent applications have been made for nanocapsules and/or nanocomposite materials inserted in devices and guide catheters. A study was also made of patents in Brazil, where the same assignees and the same country (United States) as in the survey of global patents were found to be the leading patent applicants / holders.     

Salivary bisphenol-A levels detected by ELISA after restoration with composite resin

Bisphenol-A diglycidylether methacrylate (Bis-GMA), which is synthesized from bisphenol-A (BPA), a compound with exogenous endocrine disrupter action, is widely used as a dental material. During clinical filling with sealants and composite resins, the compounds are solidified by polymerization and then used. However, it has been noted that unpolymerized monomers may become dissolved in saliva. In this study using a competitive ELISA system, we investigated the changes in the BPA concentration in saliva after restoration with composite resins. Commercial composite resins from nine companies were tested. Mixed saliva was collected from 21 subjects. Based on the dynamics of salivary BPA detected by this ELISA system, we concluded that several tens to 100 ng/ml of BPA were contained in saliva after filling teeth with composite resin but that sufficient gargling can remove it from the oral cavity. Our data suggest that sufficient gargling after treatment is important for risk management.     

Damage Resistance of Composites Based on Glass Fibre Reinforced Low Styrene Emission Resins for Marine Applications

Composites based on glass fiber reinforced low styrene emission polyester resins have been widely used over the last 10 years, in order to meet increasingly strict safety regulations, particularly in the pleasure boat industry. Previous studies of their mechanical properties suggested that although these resins are generally more brittle than traditional orthophthalic polyester resins this did not adversely affect the properties commonly used for quality control (short beam shear and tensile failure strength of mat reinforced composites). In the present paper results from a more detailed study of damage behaviour are presented. Tests include fracture toughness (K _Ic ) tests on resins, fibre/matrix interface energy, detection of composite damage initiation in tension by acoustic emission, composite delamnation (G _Ic and G _IIc ), and low energy impact. Overall the results indicate that the low failure strain of low styrene emission resins results in significantly lower composite damage resistance.