杜仲胶性质及提取研究的进展

综述了杜仲含胶细胞形态与分布,杜仲胶的主要化学性质及物理力学性质,杜肿胶的提取、分离,以及杜肿胶高分子材料的基础研究与应用开发研究的新进展;总结了杜仲胶开发的现状。     

杜仲胶提取与规模化生产现状及其产业发展面临的问题

杜仲是我国非常宝贵的战略资源,杜仲胶是带动杜仲大产业发展的核心动力。杜仲胶产业的发展不仅能够改善我国天然橡胶不足的现状,还可以为我国提供新的来源充足的后备胶种,形成以我国杜仲胶新兴产业为龙头的国际天然橡胶市场新格局。近年来,杜仲胶产业化和应用开发虽然取得突出进展,但还远不能适应形势发展的需要,究其原因是杜仲产业链的发展存在技术不完善、资金不足等一些突出问题。本文阐述了杜仲叶、树皮、果实在生长时期的含胶量变化情况,重点综述了杜仲胶的碱煮法、溶剂提取法、微生物发酵法、生物酶解法及综合法等提取技术,并综述了杜仲胶规模化生产现状,同时对杜仲胶产业发展面临的诸多问题如研发资金及研发团队的不足、橡胶基础研究与工程应用的脱节、产品标准的缺失等等进行深入分析和讨论,并提出了建议和措施着力解决发展中的关键问题,以助力杜仲胶在系统材料工程学中的开发利用,为杜仲胶产业持续发展提供参考。     

杜仲胶的研究与发展

介绍了杜仲胶发展简史和开发应用前景,综述了杜仲胶的多种提取与分离方法及工艺,阐述了对杜仲胶的结构与性能的研究以及高弹性杜仲硫化橡胶的结构,重点介绍了对杜仲胶的几种共混体系的研究：在杜仲胶与NR二元共混及与NR和顺丁胶三元共混体系中,杜仲胶对体系硫化性能以及力学性能的影响。     

杜仲胶的提取与热记忆材料制备的研究

本文采用溶剂-沉淀法,从杜仲树叶、皮、种子分离提纯得到杜仲胶,通过偏光显微镜（PLM）,红外吸收光谱（IR）等手段对杜仲胶进行了研究。发现提取的杜仲胶为α型结晶体,密度法结晶度（Xc）大于30％,为典型的球晶;通过正交设计确定了杜仲胶热记忆材料的配方,并讨论了热记忆机理。     

开发杜仲胶前景诱人

开发杜仲胶前景诱人杜仲胶是一种天然高分子材料，它存在于杜仲树的叶、皮、根中。由于杜仲胶具有强度高、透气性好、成型容易等特点，因而成为较理想的医用材料。尤其是用于骨科夹板的杜仲硫化胶，与国际新出现的合成反式聚异戊二烯相比，具有强度高、价格低的优势。用杜...     

杜仲联盟启动杜仲胶等团体标准制定工作

正杜仲产业联盟、中国橡胶工业协会杜仲综合利用工作委员会理事会扩大会3月22日在青岛召开。鉴于我国多种杜仲综合开发产品已经和即将推向市场,为推动我国杜仲产业健康发展,促进杜仲领域产品市场的有序竞争,会议决定成立相关杜仲产品标准制定工作组,尽快启动杜仲胶等团体标准的制定工作。会议经过讨论,首批成立了"杜仲胶标准制定"和"杜仲提取物标准制定"两个工作组,确定由杜仲联盟专家委员会主任、北京老爹杜仲胶集成材料研究院院长严瑞芳研究员牵头,负责杜仲胶标准制定     

首家杜仲胶集成材料研究院落户中关村

正2016年5月,北京老爹杜仲胶集成材料研究院在中关村正式挂牌成立。这是我国首家民营杜仲胶集成材料研究机构,发展方向为研究开发系列杜仲胶集成材料及其制品,为我国规模化杜仲胶生产和市场培育奠定基础。该研究院聘请著名杜仲胶专家严瑞芳教授担任院长。严瑞芳教授原为中国科学院化学所研究员,     

新型自修复杜仲胶材料问世

<正>近日,沈阳化工大学杜仲胶研究团队,研发出基于杜仲胶的自修复功能弹性体材料。他们通过向杜仲胶中引入大量动态可逆的离子或化学键,赋予其犹如生命体的自修复功能,修复效率可达90%以上。杜仲胶自修复材料修复过程     

钛白粉对未硫化生物基杜仲胶性能的影响

依据杜仲胶橡塑二重性和结晶程度,通过改变钛白粉含量,实现不同的钛白粉份数下的生物基杜仲胶材料的制备,并进行相应的力学性能测试、密度测试、DSC测试、RPA测试等。结果表明,随着钛白粉用量的增加,100%定伸应力逐渐减小,且减小的趋势越来越缓慢;钛白粉的增加能提高杜仲胶的结晶度,并且杜仲胶的分子仍会表现出良好的有序性。改性之后的杜仲胶的网状结构更加稳定。     

杜仲胶在航空轮胎中的应用技术通过鉴定

正2017年11月16日,中国石油和化学工业联合会组织专家对沈阳化工大学、湘西老爹生物有限公司和沈阳三橡股份有限公司共同完成的"杜仲胶在航空轮胎中应用关键技术"项目进行了科技成果鉴定。鉴定专家认为:该项目首次将杜仲胶应用于高速航空轮胎,开展了相关的应用基础研究,成功制备了杜仲胶航空轮胎,通过了最高速度级动态模拟试验,各项性能达到标准要求,具有创新性。针对杜仲共混胶硬度大、成型加工难度大等问题,开发成功杜仲母炼胶     

天然杜仲胶的改性及应用研究进展

杜仲胶（EUG）主要由反式聚异戊二烯组成,是一种具有良好生物相容性、橡塑二重性和优异力学性能的天然高分子材料。近年来,EUG在新型生物基材料领域备受瞩目。EUG在室温下结晶度高,表现为刚性塑料状态,极大程度限制了其在功能材料领域的应用。因此,将EUG进行物理或化学改性,进而拓宽其应用范围已成为近年来的研究热点。本文详细介绍了EUG分子链结构特点,随后从物理改性和化学改性两个方面系统论述了EUG常见的改性方法及机理,如通过与其它材料共混或环氧化改性、硫化改性等改变EUG的硬度及弹性。对EUG在绿色轮胎与公路建设、形状记忆与自修复材料、减震与吸声材料、医用材料、生物降解复合材料等新型功能材料领域的最新研究进展进行了综述,并在此基础上展望了EUG在生物基高性能材料领域的发展前景。     

杜仲胶/聚乳酸形状记忆热塑性硫化胶的制备及性能

将生物基高分子材料杜仲胶（EUG）和聚乳酸（PLA）通过动态硫化技术制备了具有形状记忆性能的热塑性硫化胶（EUG/PLA TPV）。通过扫描电子显微镜、差示扫描量热、动态力学和力学性能测试及热机械循环分析等手段分别考察了EUG/PLA TPV的微观形貌、相容性、热性能、动态力学和力学性能及形状记忆性能。结果表明,增容剂腰果酚有效改善了EUG相与PLA相之间的相容性,从而提高了EUG/PLA TPV的力学性能。当橡塑质量比为5/5时,拉伸强度为10.5 MPa,扯断伸长率达到286%,是纯PLA的约48倍。EUG/PLA TPV具备特殊的双连续相结构,可以赋予其良好的形状记忆性能,形状固定率最高达到93%左右,形状回复率最高达到98%左右。     

Highly toughened polylactide by renewable Eucommia ulmoides gum

Polylactide (PLA) derived from natural sources has attracted increasing interest and has provided a promising alternative to traditional plastics derived from petroleum sources. With no loss of environmental friendly features, PLA was highly toughened by Eucommia ulmoides gum (EUG) derived from Eucommia ulmoides oliv. The dynamic mechanical analysis, scanning electron microscopy (SEM), and differential scanning calorimetry results show that the PLA–EUG blends were immiscible systems. SEM micrographs revealed that EUG particles were well dispersed in the PLA matrix with number‐average particle diameters of 2–4 μm. The mechanical properties indicated that the tensile strength decreased with increasing EUG contents, but the elongation at break and the impact strength were enhanced. The notched impact strength of the blends improved by 5.9‐fold compared to that of neat PLA. The PLA–EUG blends exhibited distinct shear‐thinning behavior; this indicated good processability, and the storage modulus and loss modulus of the PLA–EUG blends increased with EUG content. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46017.     

Heat-responsive shape memory Eucommia ulmoides gum composites reinforced by zinc dimethacrylate

With the renewability, functionality, and biocompatibility of Eucommia ulmoides gum (EUG), shape memory polymers fabricated from EUG present the potential application in biomedical devices and sensors. In this study, heat-responsive shape memory composites were developed and reinforced by zinc dimethacrylate (ZDMA). ZDMA particles were in situ polymerized and uniformly dispersed in the EUG, showing strong interfacial interactions with EUG. The obviously improved tensile strength and storage modulus in the elastic state are attributed to the reinforcement of poly-ZDMA particles. The switching temperature of EUG/ZDMA composites changed from 50 to 29°C through altering the dicumyl peroxide and ZDMA loading. The EUG/ZDMA composites exhibited high shape fixity of 95% and shape recovery of 90%, which favors theirs biomedical applications.     

杜仲胶与合成反式-1,4-聚异戊二烯非等温结晶性能对比

本文首先通过红外光谱(IR)、核磁共振(1H-NMR)和渗透凝胶色谱(GPC)等测试手段表征了本实验选用的杜仲胶(EUG)和合成反式-1,4-聚异戊二烯(TPI)的化学组成和结构差异,进而采用差示扫描量热仪(DSC)和偏光显微镜(POM)分别测试了EUG和TPI的非等温结晶行为,Mo法研究了两者的非等温结晶动力学并进行了对比。结果表明,Mo法处理EUG和TPI的非等温结晶过程较为理想。非等温结晶动力学研究得到的t1/2和FT等结晶参数表明,随降温速率的增加,EUG和TPI的结晶速率增大,EUG结晶速率快于TPI。根据Kissinger方程求得EUG的结晶活化能为102.8 kJ/mol,TPI为97.4 kJ/mol。这些非定温结晶性能的差异主要来源于二者不同的合成机理所造成的杂质种类、分子链端基以及分子量分布的不同。     

用杜仲胶/碳纳米管改性环氧树脂制备导电防腐涂料及其性能

以杜仲胶(EUG)和环氧树脂(E-51)为涂层基质、碳纳米管为导电填料制备了导电防腐涂料,考察了 EUG用量对复合涂层导电性和耐腐蚀性的影响.采用差示扫描量热仪和动态热机械分析仪研究了复合涂层的热性能,用四探针测试仪研究了导电性能,分别通过电化学阻抗谱及盐雾测试和附着力测试研究了耐腐蚀性和附着力.结果表明,当EUG用量...     

A combined experimental and molecular dynamics simulation study on the miscibility of <Emphasis Type="Italic">Eucommia ulmoides</Emphasis> gum with butadiene rubber

The miscibility of Eucommia ulmoides gum (EUG) blended with butadiene rubber (BR) was investigated by atomistic molecular dynamics (MD), mesoscopic dynamics (MesoDyn) simulations and melt-mixing in an open two-roll mill at 80°C and 50 rpm. Seven EUG/BR blends (with weight ratios of 80/20, 70/30, 50/50, 30/70, and 20/80), as well as pure EUG and BR, were examined. Flory Huggins parameters, phase diagrams, the radial distribution function, free energy, and order parameters were computed for different blends using atomistic simulations to predict blend miscibility. The simulation results showed that all the EUG/BR blends have good miscibility. However, the mechanical properties of the vulcanized EUG/BR blends improved with the addition of EUG into BR matrix, and scanning electron microscopy (SEM) micrographs of the fractured surface had also revealed that the phase separation was not found, but which indicated EUG/BR had good miscibility. All the simulation results are qualitatively consistent with the experimental results, which demonstrates that the modeling strategies in this study may provide a powerful tool for predicting the miscibility and mesoscopic morphology of polymer blends.     

导电炭黑/杜仲胶复合材料电磁屏蔽性能的研究

采用机械共混法制备了导电炭黑/杜仲胶复合材料,研究炭黑用量对复合材料电性能和电磁屏蔽性能的影响。结果表明：随着炭黑用量的增加,复合材料的导电率增大,当炭黑用量为25份时,导电率达到3.3S/cm,导电率遵循导电逾渗规律;复合材料的Payne效应越来越大,有利于形成稳定的导电网络;复合材料的拉伸强度逐渐增大后略微降低,断裂伸长率先增加后逐渐下降。复合材料的屏蔽效能增大,当炭黑用量为20份时,屏蔽效能最高能达到33.2dB,可以满足一般工业或者商业用电子设备的要求。     

Bio-Based,Self-Crosslinkable Eucommia ulmoides Gum/Silica Hybrids with Body Temperature Triggering Shape Memory Capability

At present, the synthesis of body temperature triggering shape memory polymers usually requires elaborate structural design, which limits their wide application. Herein, starting from bio-based Eucommia ulmoides gum (EUG), a series of EUG/silica hybrids (ESHs) are prepared through a facile one-pot process, in which EUG is epoxied and then self-crosslinked with SiO₂ by epoxy ring-open reaction. Varying the amount of H₂O₂, the shape memory transition temperature (T_trans) of ESHs is adjusted to 47.4–36.6 ℃, which is close to human body temperature (37 ℃). Among them, ESH-17 exhibited the best body temperature triggering shape memory ability (T_trans = 36.6 ℃), which can restore the permanent shape within 60 s at 37 ℃ with a shape fixity ratio of 99% and shape recovery ratio near 100%. In addition, the shape memory mechanism is discussed and shows some application scenarios of ESHs. The as-produced materials can be used as smart biomaterials such as self-tightening sutures, self-sealing root canal filling materials, and so on.