橙色管材专用PE100级树脂的开发

以通过PE100级认证的管材专用高密度聚乙烯(牌号为TUB121N3000)为基体,紫外光老化和热氧老化时间为核心评价指标,开发出性能优异的橙色管材专用PE100级树脂。结果表明:橙色母料2544或2029B用量为最小单位用量的2倍,受阻胺光稳定剂、紫外光吸收剂、复合抗氧剂质量比为2∶3∶4时,制备的橙色管材专用PE100级树脂的氧化诱导时间大于30 min,颜料分散级别小于2级,紫外光老化2 000 h后色差小于3,烘箱老化后断裂标称应变保留率大于50%。     

PP-R树脂专用色母粒的研制

通过筛选颜料、分散剂和载体，采用两步法工艺路线制备出无规共聚聚丙烯(PP—R)树脂专用色母粒，并详细讨论了色母粒的性能指标以及色母粒对PP—R管材专用树脂性能的影响。实验结果表明，研制出的色母粒与PP—R树脂兼容性较好，提高了PP—R管材专用树脂的加工性能和力学性能。     

抗老化PP扁丝编织土工布专用料的研制

选择国产基础树脂与稳定剂，采用碳弧灯和B型荧光紫外灯人工加速老化试验，研究了光稳定剂品种、用量、与抗氧剂的复配及色母粒、重钙母粒对专用料老化性能的影响。与添加Ciba精化公司MB218母粒的抗老化聚丙烯(PP)性能的对比及应用试验结果表明，PP扁丝编织土工布抗老化性能优良。     

PE-RT专用色母料的研制

采用双螺杆挤出机制备出耐热聚乙烯(PE-RT)专用色母粒.考察了PE-RT专用色母粒对PE-RT基料材料力学性能、耐环境应力开裂性、加工流动性的影响.结果表明:该色母粒对PE-RT基料材料力学性能、耐环境应力开裂性、加工流动性的影响不大,综合性能有所提高.     

PP-R、PP-B管材料专用色母粒的研制

采用无毒、耐候性好、热稳定性高的颜料制得PP－R、PP－B管材料专用色母粒，考察了色母粒对PP－R、PP－B管材料力学性能、耐热性、耐光性、卫生安全性的影响。结果表明：该色母粒对PP－R、PP－B管材专用料的力学性能影响不大，采用该色母粒无需改变PP－R、PP－B管材的生产工艺。     

新型载体树脂在色母粒中的应用研究

对不同熔体质量流动速率（MFR）的同种聚乙烯树脂在色母粒应用方面进行了比较。结果表明：载体树脂MFR的差别对色母粒的质量、加工性能和应用影响较大；高MFR树脂制备的色母粒，加工性能较好，颜料在色母粒中的分散程度较高，但对其他树脂进行着色的效果不理想。因此，应该从色母粒中颜料的分散和色母粒与着色树脂的相容性两个方面进行新型色母粒用载体树脂的开发。     

透明聚丙烯专用色母粒的研制

通过对载体树脂、颜料和分散剂的筛选,探讨了不同载体树脂、颜料和分散剂对着色制品透光率及其流变性、耐候性的影响,研制出了性能优良的透明聚丙烯专用色母粒。开发出的色母粒不仅加工简单、使用方便,而且具有较强的着色能力,更为重要的是它几乎不影响体系的透光率。     

LDPE粉末涂料专用树脂的应用

研究了低密度聚乙烯粉末涂料专用树脂LD400在粉末涂料上的应用配方,及其对树脂力学性能、热性能及耐环境应力开裂性能的影响,探讨了该专用树脂的加工粉末涂料性能、老化性能、表面性能等综合性能.结果表明,LD400的流动性能好、硬度高、易于粉碎,涂塑制品的镜面光泽度达到75.9%,优于对比样涂塑制品.     

色母粒载体专用树脂TJZS—2433／2650F的物理性能和应用特性探讨

介绍天津石化公司乙烯厂开发的色母粒载体专用树脂TJZS-2433/2650F其物理性能，并通过对相关试验和测试结果的研究探讨了其在色母粒中的应用特点，就其在色母粒中的应用范围提出了建议。     

聚乙烯微滴灌管专用料的研制

研制了4种聚乙烯微滴灌管专用料,其综合性能与进口微滴灌管专用树脂的相当,许具有较好的耐光氧老化性能．炭黑在专用料巾分散良好。4种专用料经过自然光和紫外光老化后,其中3种专用料的托伸强度和断裂伸长率保留率与进口微滴灌管专用树脂的相当,均超过80％;4种专用料的出口膨胀系数与进口微滴灌管专用树脂相当．为1．65～0.80,因此其成型加工性能较好,均能满足徽滴灌管挤出工艺条件,微滴灌管挤管速度超过100m/min.     

Life performance evaluation of electron beam-curable polyurethane pressure-sensitive adhesive tape for medical applications

Devices for medical application require materials to perform at the highest standard over an extended period of time, as many products may be stored more than a year before their use. The performance of such devices can be adversely affected, if the materials of construction they are made of loose their efficiency during storage. Therefore, material aging information is very important in order to ensure the product quality. The quality of the product can be evaluated either by doing the actual storage studies time to time or accelerated aging studies can be simulated in the laboratory to reduce the study time and to know performance of the product well in advance. The accelerated aging studies thus have immense importance before commercialization of any product. In the present study an attempt has been made to assess life time expectancy in terms of its performance of a microporous pressure sensitive adhesive (PSA) tape made of polyurethane (PU) acrylate by e-beam irradiation process. The accelerated aging studies were carried out for different time intervals at different temperatures and the performance of the PU-PSA tape was evaluated in terms of shear adhesion strength.     

偶联剂B对RTV硅橡胶粘接强度的影响

为了提高RTV硅橡胶与金属材料的粘接强度 ,对金属材料表面采用偶联剂处理 ,筛选了多种偶联剂 ,进行了稳定性和加速老化试验 ,测试了试件的剪切强度和扯离强度 ,结果表明偶联剂B具有较佳的性能 ,不仅能够提高粘接强度 ,而且粘接强度稳定     

苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青的老化性能

考察了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)和加入含硫稳定剂的SBS改性沥青老化后的动态力学性能、黏度变化和低温物理性能。结果表明,SBS与含硫稳定剂的加入改善了老化后沥青的高温性能;老化后的改性沥青表现出更好的高温刚性,蠕变劲度降低,蠕变速率增大,老化后沥青的低温性能提高,且长期使用性能良好。     

受阻胺类光稳定剂改性文物保护材料B72

为了提高B72文物保护材料的耐光性能,采用HALS-622等6种受阻胺光稳定剂对丙烯酸类文物保护材料B72进行改性。结果表明,HALS-5060稳定剂在添加后及老化过程中颜色明显变黄,不宜用作B72改性材料。高相对分子质量(简称分子量,以下同)受阻胺HALS-622、HALS-944比低分子量受阻胺HALS-480、HALS-508和HALS-292稳定效果好,尤其是低碱性的HALS-622受阻胺。因此,采用高分子量、低碱性的受阻胺改性B72是延长其使用寿命、对文物进行有效保护的新途径。     

EVALUATION OF THE LONG-TERM DURABILITY OF HIGH-PERFORMANCE POLYIMIDE ADHESIVES FOR BONDING TITANIUM

This study was conducted to investigate the performance of the Ti-6Al-4V/FM-5 adhesive bonded system for potential applications on high-speed aircraft. The long-term environmental aging effects on Ti-6Al-4V/FM-5 bonded joints and neat FM-5 and PETI-5 resin specimens were investigated. Dynamic mechanical analysis (DMA) and uniaxial tensile testing using dogbone samples were performed on neat FM-5 and PETI-5 resin specimens before and after high-temperature aging in both ambient and reduced pressure environments. Mode I fracture testing was also performed on beam specimens fabricated with mat-scrim-cloth-supported films of FM-5 adhesive bonding titanium adherends prior to and after environmental aging. Experimental results revealed that both physical aging, which is reversible, and irreversible chemical aging took place simultaneously in the adhesive systems, and both types of aging could contribute to loss in adhesive bond performance. Furthermore, the properties of several different Ti-6Al-4V/FM-5 systems, prepared using different surface pretreatment methods and different supportive matrices of FM-5 resin, were compared in this study, and the effect of mode-mixity on the fracture toughness of the adhesive-bonded systems was also evaluated by conducting double cantilever beam (DCB), end-notched flexure (ENF), and mixed-mode flexure (MMF) tests. The creep behavior of the Ti/FM-5 bonded joint was also investigated by performing thick adherend shear tests.     

EVALUATION OF THE LONG-TERM DURABILITY OF HIGH-PERFORMANCE POLYIMIDE ADHESIVES FOR BONDING TITANIUM

This study was conducted to investigate the performance of the Ti-6Al-4V/FM-5 adhesive bonded system for potential applications on high-speed aircraft. The long-term environmental aging effects on Ti-6Al-4V/FM-5 bonded joints and neat FM-5 and PETI-5 resin specimens were investigated. Dynamic mechanical analysis (DMA) and uniaxial tensile testing using dogbone samples were performed on neat FM-5 and PETI-5 resin specimens before and after high-temperature aging in both ambient and reduced pressure environments. Mode I fracture testing was also performed on beam specimens fabricated with mat-scrim-cloth-supported films of FM-5 adhesive bonding titanium adherends prior to and after environmental aging. Experimental results revealed that both physical aging, which is reversible, and irreversible chemical aging took place simultaneously in the adhesive systems, and both types of aging could contribute to loss in adhesive bond performance. Furthermore, the properties of several different Ti–6Al-4V/FM-5 systems, prepared using different surface pretreatment methods and different supportive matrices of FM-5 resin, were compared in this study, and the effect of mode-mixity on the fracture toughness of the adhesive-bonded systems was also evaluated by conducting double cantilever beam (DCB), end-notched flexure (ENF), and mixed-mode flexure (MMF) tests. The creep behavior of the Ti/FM-5 bonded joint was also investigated by performing thick adherend shear tests.     

Impact of deposit aging and surface roughness on thermal fouling: Distributed model

A kinetic model was recently proposed to describe the effect of aging on deposit thermal conductivity and the thermal performance of a shell‐and‐tube heat exchanger undergoing crude oil fouling. The model is adapted for implementation within a dynamic, distributed system with spatial and temporal distributions, relaxing several of the previous assumptions. The evolution of surface roughness is also considered, using conjectural linear and asymptotic functions. Simulations are performed for a single tube representative of a refinery exchanger. The results demonstrate the substantial effects over time of aging and roughness on heat transfer and pressure drop. Roughness effects yield apparently negative initial fouling resistances, as reported in some experimental tests. The importance of accounting for roughness dynamics in short time scale pilot plant scale tests and aging over longer time scales in industrial applications is highlighted. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Thermal-oxidative aging performance and life prediction of polyethylene pipe under cyclic and constant internal pressure

To study the aging characteristic of the polyethylene (PE) 100 pipe under constant and cyclic internal pressure, a new accelerated thermal-oxidative aging test equipment was developed. Thermal-oxidative aging behaviors of PE pipe under constant pressure and cyclic pressure were studied in various temperatures (80, 95, and 110 °C) by accelerated aging tests. The tensile test result shows that the fracture strength of PE pipe decreases as the aging time prolongs. Meanwhile, the pipe aged in the higher temperature behaves faster decreasing rate. A faster decreasing rate is also observed under the condition of cyclic pressure, compared to that under constant pressure. The thermal stability of the pipe gradually reduces and the reducing rate under cyclic pressure is higher than that under constant pressure. The result of infrared spectroscopy test suggests that oxygen-containing groups (i.e., CO) are formed on the surface of PE pipes, indicating that oxidative degradation phenomenon of PE pipes occurs during the aging process. Furthermore, based on the measured result of fracture strength, lifetime prediction models of PE 100 pipe under constant pressure and cyclic pressure are proposed. The result shows that the lifetime of PE 100 pipes obviously decreased under cyclic pressure, and it is 27.96% shorter than that under constant pressure. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47766.     

由聚乙烯罩袋的氙灯老化测试推算其自然气候曝露性能

利用平板式氙灯试验箱,对低密度聚乙烯(LDPE)吹塑罩袋进行氙灯老化测试,发现有关低密度聚乙烯罩袋在抗光老化性能方面的一些规律。结合最小偏差原理等统计学方法,由低密度聚乙烯罩袋的较短时间的氙灯老化测试数据即可推算其在户外一年自然气候曝露的性能。该方法置信度高,且方便、快捷,可作为推算高分子聚合材料在户外抗老化性能的理论依据。应用于塑料配方的筛选,可降低长期人工老化的成本、结果再现性好。     

Mechanistic insights into the thermal–mechanical aging of the interface of cross-linked polyethylene/silicone rubber

Cable accessory has the interface formed by cross-linked polyethylene (XLPE)/silicone rubber (SiR), which is prone to surface discharge and thus causes the failure of cable system. This article conducts the simulated experiment of thermal–mechanical aging on the interface of XLPE/SiR. The interfacial breakdown and dielectric properties under different aging states are analyzed. It is found the interfacial aging process of XLPE can be divided into the recrystallization stage and the oxidation reaction stage. The former contributes to the interfacial roughness and thus the better insulating performance, whereas the latter leads to degradation of interface, and thus the worse insulating performance. In addition, combined with the established electric field model for the interface, the differences between thermal–mechanical aging and individual thermal aging on the interface are discussed. The sample under thermal–mechanical aging reaches the maximum interfacial breakdown voltage later than that under individual thermal aging, but their performance tends to be consistent in the later stage of aging.