聚乙烯管材料用抗氧剂评价

采用DSC法[1]测定高密度聚乙烯(HDPE)管材料的抗热氧性能,以氧化诱导期为指标评价抗氧剂功效。试验表明：硫代受阻酚抗氧剂736优于抗氧剂1010,且与炭黑配合有良好的协同效应。     

加工工艺对聚乙烯热收缩膜性能的影响

以低密度聚乙烯(LDPE)、线型低密度聚乙烯(LLDPE)和高密度聚乙烯(HDPE)为原料,采用吹塑成型法制备了热收缩膜。研究了原料配方、模具吹胀比、吹膜机牵伸比、挤出温度和膜泡冷却时间等因素对聚乙烯热收缩膜力学性能和透明度的影响。结果表明:与加入HDPE相比,配方中加入LLDPE的原料所生产的热收缩膜的综合性能较好;随着机组运行牵伸比的增大,PE热收缩膜的拉伸性能、收缩率和透光率均呈上升趋势;随着模具吹胀比的增大,PE热收缩膜的纵向收缩率下降,横向收缩率和透光率均上升;随着挤出机工艺温度的升高,PE热收缩膜的纵、横向收缩率同时上升;随着膜泡冷却时间的延长,PE热收缩膜的纵、横向收缩率和透光率均下降。     

N2保护对加工PP和HDPE的影响

探讨了在N2保护和无N2保护下不同抗氧剂体系对聚丙烯(PP)、高密度聚乙烯(HDPE)性能的影响.结果表明,造粒加工过程中,在N2保护下加入抗氧剂,PP的熔体流动速率变化率最高可下降46.1%,氧化诱导期最大可延长3.3 min;HDPE的氧化诱导期最大可延长19.3 min,提高了合成树脂的加工稳定性和抗氧化效果.     

抗氧剂体系对聚乙烯性能的影响

研究了聚乙烯中加入不同比例的酚类主抗氧剂1010和亚磷酸酯类辅助抗氧剂168后,颜色、氧化诱导时间、熔体流动速率的变化.结果表明:辅助抗氧剂168加入量恒定时,随主抗氧剂1010加入量增加,聚乙烯的氧化诱导时间增加;随着挤出次数增加,聚乙烯黄色指数呈上升趋势;主抗氧剂1010加入量为200 mg/kg时,材料的耐热氧老...     

炭黑对给水用聚乙烯管材物理性能的影响

采用不同炭黑比例的聚乙烯(PE)管材,研究了炭黑对PE管材物理性能的影响.结果表明,炭黑对PE管材的氧化诱导时间(OIT)、拉伸性能、密度均有一定的影响;相同的原料和工艺下,密度与炭黑含量呈线性关系,随着炭黑含量的增加,密度也随之增大;在炭黑含量为1.43％～3.51％区间内,随着炭黑分散等级的增大,OIT变小,并且与...     

循环载荷作用下聚乙烯管材老化性能及寿命预测

运行过程中的循环载荷作用会对聚乙烯管材的使用寿命产生影响。为探究聚乙烯(PE)管材在循环载荷影响下的预期寿命,搭建PE管材热氧老化实验平台,对试验PE管施加循环内压载荷,并进行不同老化条件下的加速老化试验。测试老化PE管材的断裂伸长率及氧化诱导期,再分别基于PE管材断裂伸长率及抗氧剂消耗对循环载荷作用下的PE管材使用寿命进行预测。结果表明,在循环载荷作用下,以PE管材断裂伸长率及氧化诱导期为考察指标的预期使用寿命分别为90.04 a和118.51 a,相比基于抗氧剂损耗的寿命预测,基于力学性能的寿命预测结果更偏保守。     

抗氧剂对聚乙烯光降解膜结构及性能的影响

采用紫外光加速老化的方法研究了抗氧剂1010对聚乙烯(PE)光降解膜的影响,并通过红外光谱、紫外光谱分析和拉伸性能测试对老化前后的薄膜的结构和性能进行了研究。结果表明,抗氧剂1010能抑制PE的光氧化降解,且导致薄膜光降解过程中羰基化合物的生成量和类型减少;添加抗氧剂1010的光降解薄膜降解的诱导期延长,PE光降解膜紫外照射3 d后其断裂伸长保留率小于80 %,而添加0.3 %（质量分数,下同）抗氧剂1010的PE光降解膜照射4~5 d后其断裂伸长保留率小于80 %。     

新型芳胺类抗氧剂与聚乙烯相容性研究

采用傅里叶红外光谱(FTIR)和氧化诱导期(OIT)对芳胺类抗氧剂与聚乙烯材料的相容作用进行研究。实验结果表明:随着温度的升高,抗氧剂与聚乙烯材料的相容量增加,其中防老剂D与聚乙烯材料的相容量增加最大。抗氧剂浓度对其与聚乙烯材料的相容作用几乎无影响。随着实验时间的延长,抗氧剂与聚乙烯材料的相容量增加,其中新型芳胺抗氧剂的相容速率最慢,但相容性最好。     

高密度聚乙烯防渗膜在石化污水管线上的应用

通过高密度聚乙烯（HDPE）防渗膜在石化项目地管上的应用,介绍了HDPE土工膜的主要施工方法、焊接原理、特殊部位的处理要点及其焊缝检测方法。     

聚乙烯增韧改性研究

聚乙烯(PE)作为五大合成树脂之一,也是我国产能最大,进口量最多的和合成树脂。凭借其良好的加工性能,力学性能,耐化学腐蚀性能,耐低温性能,并且具有来源广,价格低等优势,在薄膜,包装,管材,片材,纤维等领域得到了广泛的应用。正是因为聚乙烯树脂的耐化学腐蚀性好,耐低温,不透水,价格低廉的优点,使其在建筑物防水材料上有了很大的应用前景。但聚乙烯种类较多,不同种类的聚乙烯性能和价格差别大,单一种类的聚乙烯很难满足建筑防水材料的性能要求。通过PE/POE、PE/EVA共混改性,改善聚乙烯材料的韧性,强度,黏结性,低温弯折性等性能,达到建筑用防水片材的国家标准并且使产品具有一定的经济效益是本次研究的主要目的。讨论了HDPE/LLDPE/POE和HDPE/LLDPE/EVA共混改性体系中不同牌号聚乙烯的配比以及POE(或EVA)混合比例对共混材料各项性能的影响。通过对共混改性之后材料拉伸性能,撕裂强度,不透水性,低温弯折性,热空气老化,碱溶液老化等性能测试。发现原料配比与性能之间的关系,进而筛选出各项指标都达到甚至超过国家标准的产品配方,初步取得了不错的效果。     

Influence of wall number and surface functionalization of carbon nanotubes on their antioxidant behavior in high density polyethylene

Carbon nanotubes (CNTs) are extensively incorporated as reinforcement into polymeric materials due to their extraordinary properties. The antioxidant ability of CNTs in high density polyethylene (HDPE) was studied. Single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) were involved to investigate the influence of wall number and surface functionalization of CNTs on their antioxidant behavior in HDPE. Based on measurements of the oxidation induction temperature and oxidation induction time of CNT/HDPE composites, it is found that the antioxidant ability of the three kinds of CNTs is in the following order: MWCNTs-OH > MWCNTs > SWCNTs. The antioxidant ability and mechanism of CNTs are further examined by electron spin resonance spectra and Raman spectra. It is observed that the antioxidant behavior of CNTs obeys a free radical scavenging mechanism. The order of the radical scavenging efficiency and the defect concentration for CNTs are in good agreement with that of their antioxidant ability in HDPE. With more walls and surface hydroxyl groups, the CNTs have more structural defects and exhibit higher antioxidant ability. The study raises the possibility that CNTs can improve antioxidant properties as well as mechanical properties of polymer matrix.     

宽峰高相对分子质量高密度聚乙烯专用料的研制

通过淤浆法小试聚合装置合成了不同相对分子质量的高密度聚乙烯粉末,对聚合工艺条件对产物物性的影响进行了研究。同时,考察了不同相对分子质量的聚乙烯共混合成宽峰聚乙烯专用料的规律。结果表明:通过调整聚合工艺条件,在淤浆法小试聚合装置聚合产物的相对分子质量可调;不同相对分子质量的聚乙烯粉末共混可以制备宽峰HDPE;合成的宽峰HDPE专用料的综合力学性能优良,在树脂研究院进行加工,性能良好。     

宽峰高相对分子质量高密度聚乙烯专用料的研制

通过淤浆法小试聚合装置合成了不同相对分子质量的高密度聚乙烯粉末,对聚合工艺条件对产物物性的影响进行了研究.同时.考察了不同相对分子质量的聚乙烯共混合成宽峰聚乙烯专用料的规律.结果表明:通过调整聚合工艺条件.在淤浆法小试聚合装置聚合产物的相对分子质量可调;不同相对分子质量的聚乙烯粉末共混可以制备宽峰HDPE:合成的宽峰HDPE专用料的综合力学性能优良,在树脂研究院进行加工,性能良好.     

Linking Antioxidant Depletion with Material Properties for Polyethylene Pipes Resins

Plastic pipes used in gas distribution networks are typically made from polyethylene (PE) and are stabilized against degradation by antioxidants. Over time, the antioxidant is consumed and the polymer integrity can become compromised. The rate of antioxidant depletion can be dependent on the specific grade of PE and the surrounding environment. In this research, the crystallinity, tensile strength, Young's modulus, and strain at break were measured for the four most commonly used PE pipe resins in the Australian natural gas distribution network as a function of antioxidant content. A relationship between the changes in material properties with antioxidant consumption was established. By measuring the carbonyl index (CI), which quantifies the amount of degradation products present, and linking this with the oxygen induction time (OIT), it was found that three clear regions exist for all investigated PE resins. These distinct regions of the OIT–CI relationship correlate with regions of substantially different rate of change in material properties, and hence indicate a measure of the integrity of the PE. POLYM. ENG. SCI., 60: 323–329, 2019. © 2019 Society of Plastics Engineers     

聚苯乙烯／聚乙烯共混体系的研究

讨论了不同第三组分和不同种聚乙烯对以聚苯乙烯为基质的ＰＳ／ＰＥ共混体系结构和性能的影响，发现苯乙烯－丁二烯－苯乙烯嵌段共聚物和苯乙烯－氢化丁二烯－苯乙烯嵌段共聚物作为第三组分对ＰＳ／ＰＥ共混体系均具有增容作用，用ＳＢＳ的效果比ＳＥＢＳ好，而ＳＢＳ的结构对增韧效果的影响不大。在ＳＢＳ存在下，ＬＬＤＰＥ对ＰＳ增韧效果最好，ＨＤＰＥ次之，ＬＤＰＥ最差。     

Evaluation by IR spectroscopy of the degradation of different types of commercial polyethylene exposed to UV radiation and domestic compost in ambient conditions

Different types of commercial polyethylene films, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and biodegradable polyethylene (BIO-PE), were exposed to UV-B radiation at different exposure time and domestic composting during spring and fall at ambient conditions. The effects of UV-B radiation and domestic composting on LDPE, HDPE, and BIO-PE degradation were characterized by FTIR spectroscopy. LDPE, HDPE, and BIO-PE exposed to UV-B radiation underwent photo oxidation reactions leading to the formation of carbonyl (CO) and vinyl (CH₂CH) groups and hydrophilic surface modification. Also, the exposure of LDPE, HDPE, and BIO-PE to domestic composting at ambient conditions at different seasons suffered biodegradation reactions leading to the formation of polysaccharides. In both different seasons LDPE, HDPE, and BIO-PE underwent partial biodegradation, remaining in the domestic composting as unwanted polymer debris. However, biodegradation in domestic composting is not recommended as feasible disposal routes for nonbiodegradable and commercially labeled as biodegradable PE.     

用废木粉增强聚乙烯的研究

本研究采用废木粉为填料增强改性高密度聚乙烯。评价了马来酸酐接枝高密度聚乙烯（MAH-g-HDPE）对聚乙烯基木塑复合材料的增客效果，研究了木粉含量对复合材料力学性能和其它性能的影响，详细阐述了木粉的增强作用机理。研究结果表明：MAH-g-HDPE可显著增进憎水性基质和亲水性木粉之间的界面相互作用，明显改进复合材料的力学性能；在使用适当相客剂的情况下，木粉可明显提高聚乙烯的拉伸强度、弯曲强度和弯曲模量，具有良好的增强效果；当木粉含量为60％时，复合材料的拉伸强度、弯曲强度、弯曲模量分别高达38MPa、54MPa和3500MPa，若与纯基质相比，分别提高了43．4％、176％和283％。这些实验结果表明，木粉对聚乙烯具有明显的增强效果。     

改性大洋黏土填充聚乙烯的力学性能研究

为确定大洋黏土的实际应用效果,对北太平洋东部的大洋黏土沉积物进行悬浮扩散提纯、硅烷偶联剂干法改性后,设计了一系列高密度聚乙烯填充实验,利用冲片机制备相应的聚乙烯复合材料进行拉伸实验,结果表明:复合材料的拉伸强度和断裂伸长率随着黏土用量的增加呈现完全相反的变化趋势,填充效果较好的黏土用量约为2%,双辊混炼的效果略胜于单螺杆挤出;同时,添加相容剂和抗氧剂对于改善复合材料力学性能的意义不大。     

辛烯共聚地暖管专用料抗氧体系优化研究

介绍了耐热聚乙烯管材PE-RT树脂抗氧剂筛选,在溶剂中溶解度,借助DSC分析仪器,对国内外PE-RT树脂进行氧化诱导期测试,对比分析这些树脂的抗氧化性能,提出地暖管产品优化方案,生产结果表明,抚顺石化辛烯共聚耐热聚乙烯管材树脂氧化稳定性较好。     

Effect of Oxidized Polyethylene Additives on Structure and Transport Properties of Polyethylene Porous Films

Porous films of high density polyethylene (HDPE) and its blends with oligomeric oxidized polyethylene (OxPE) were prepared. The effect of the additive on porous structure and mechanical properties was investigated. Degree of crystallinity, pore size distribution, specific surface, gas and liquid permeability were measured for permeable samples. Changes in porous structure and mechanical properties of the samples upon changes of additive content have been studied. It was established that oxidized PE additive is located in intercrystalline amorphous regions, and hinders pore formation.