Self-Assembly of Highly Immiscible Polymers Using Balanced Surfactants

使用平衡表面活性剂自组装高度不混溶聚合物

• 批准号: 0201211
• 负责人: Nitash Balsara
• 金额: $ 5万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0201211&HistoricalAwards=false
• 关键词: Self; Assembly; Highly; Immiscible; Polymers; Self; Assembly; Highly; Immiscible; Polymers

SELF-ASSEMBLY OF HIGHLY IMMISCIBLE POLYMERS USING BALANCED SURFACTANTSThe PI's objective is to create a library of surfactants for controlling the nano-scale self-assembly in mixtures of highly immiscible polymers. This will enable the creation of new nano-structuredpolymer materials. It may also enable reusing commingled polymeric waste. The proposed approach represents a risky departure from the large body of previous experimental and theoretical work in this field which relied of the surfactancy of A-B copolymers for organizing mixtures of A and B homopolymers. It is now recognized that these types of copolymers can only organize interfaces if the homopolymers are weakly immiscible. The surfactant that will be uses in the study is a balanced A-C block copolymer. The notion of balance is adapted from the rich literature on surfactancy in aqueous systems. Nonionic surfactants with balanced hydrophobic and hydrophilic character have been successful in creating nano-scale organization in oil/water mixtures in spite of their high degree of incompatibility. The goal is to apply this principle to polymers. The proposed experiments will be conducted on mixtures of highly immiscible polyolefins, polybutene (PB) and polyisobutylene (PIB). The PI will use a polybutene-block-head-to-head polypropylene (PB-PP) copolymer as a surfactant. The objective is to demonstrate that PB/PIB/PB-PP blends exhibit the rich self-assembly characteristics found in aqueous systems. The PI chose this system because the magnitude and sign of the temperature dependence of the PB/PP and PIB/PP Flory-Huggins interaction parameters are (approximately) equal and opposite, respectively. Model polymers required for this study will be synthesized by anionic and cationic polymerization. Self-assembly will be studied by small angle neutron scattering, light scattering, and electron microscopy.IMPACT STATEMENTThis proposed research on balanced surfactants holds the potential of introducing radically new technology for controlling the morphology of polymer blends. It will enable the creation of new blended materials from industrially important polymers such as polyisobutylene (a polymer of considerable current importance because of its use in the manufacture protective garments for working in chemically and biologically contaminated areas). Industrial production of nanostructured blends of electrically conducting and non-conducting polymers may also be enabled by the proposed research. The approach of using balanced surfactants is inspired by the efficacy of synthetic and natural surfactants in aqueous systems. However, the scientific challenge of applying principles learned in aqueous systems to hydrocarbon polymers is considerable because of the difference in fundamental intermolecular interactions. Interactions with water molecules are dominated by their permanent dipole and specific interactions such as hydrogen bonding. The SGER proposal seeks to explore the possibility of designing balanced surfactants in the absence of these interactions.

使用平衡表面活性剂的高度不混溶的聚合物的自组装PI的目标是创建一个表面活性剂库，用于控制高度不混溶的聚合物混合物中的纳米尺度自组装。这将使创建新的纳米结构聚合物材料。它也可能使重复使用混合的聚合物废物。所提出的方法代表着与该领域的先前实验和理论工作的大体系有风险的不同，这依赖于A-B共聚物的表面作用，用于组织A和B均聚物的混合物。现在已经认识到，这些类型的共聚物只能在均质物质弱不混溶的情况下组织界面。研究中将使用的表面活性剂是平衡的A-C块共聚物。平衡的概念是从水性系统中表面性的丰富文献中改编而成的。具有均衡疏水性和亲水性特征的非离子表面活性剂已成功地在油/水混合物中建立纳米级组织，尽管它们具有高度的不兼容性。目的是将该原理应用于聚合物。提出的实验将在高度不混溶的聚烯，多丁烯（PB）和聚异丁基（PIB）的混合物上进行。 PI将使用多丁烯 - 块状 - 对头聚丙烯（PB-PP）作为表面活性剂。 目的是证明PB/PIB/PB-PP的混合物表现出在水性系统中发现的丰富的自组装特征。 PI之所以选择该系统，是因为PB/PP和PIB/PP Flory-Huggins相互作用参数的幅度和符号分别（大约）相等和相反。本研究所需的模型聚合物将通过阴离子和阳离子聚合合成。自组装将通过小角度中子散射，光散射和电子显微镜进行研究。Impact语句这一提出的对平衡表面活性剂的研究具有引入根本新技术来控制聚合物混合物的形态。 它将从工业上重要的聚合物（例如聚异生物）（一种相当重要的聚合物（由于它在制造保护服装中用于化学和生物学污染的地区）中使用，从而创建新的混合材料（一种相当重要的聚合物）。 拟议的研究也可以实现电导导电和非导电聚合物的纳米结构混合物的工业生产。 使用平衡表面活性剂的方法是受水系统中合成和天然表面活性剂功效的启发。 但是，由于基本分子间相互作用的差异，应用水性系统中学习的原理的科学挑战是相当大的。 与水分子的相互作用由它们的永久性偶极子和特定相互作用（例如氢键）主导。 SGER提案试图探索在没有这些相互作用的情况下设计平衡表面活性剂的可能性。