NANODOMAIN FORMATION IN A LIQUID POLYMER BLEND : THE INITIAL STAGES OF PHASE SEPARATION
NANODOMAIN FORMATION IN A LIQUID POLYMER BLEND : THE INITIAL STAGES OF PHASE SEPARATION
复制标题
液体聚合物共混物中纳米域的形成：相分离的初始阶段
DOI：
10.1063/1.470183
复制
发表时间：
1995
影响因子：
4.4
通讯作者：
M. Fayer
中科院分区：
文献类型：
--
作者：
A. Marcus;Deborah M. Hussey;Nathan A. Diachun;M. Fayer
利用电子激发输运（EET）研究了无规共聚物和均聚物二元共混物的纳米结构形态。所采用的实验体系是一种共聚物，6.5%无规聚（甲基丙烯酸甲酯- co - 2 -乙烯基萘）[P(MMA - 2VN)]，无规聚（醋酸乙烯）（PVAc）。在EET实验中萘基团作为发色团。制备的混合物使得初始P（MMA‐2VN）链在PVAc矩阵中随机分布。当PVAc中的低浓度P（MMA - 2VN）混合物保持在熔融态（T≥T g）的恒定温度下（高于发生相分离的温度）时，纳米畴形成。在熔体中，链扩散，P（MMA‐2VN）链聚集，直到温度低于tg淬火。用时间分辨荧光去极化测量检查了所得结构域的结构，并使用分析理论对相互作用的聚合物链之间的EET模型进行了分析。理论与数据的一致性很好。分析结果表明，纳米结构域对应的聚集体的特征尺寸等于共聚物的旋转半径R g。测定了在不同条件下制备的聚集体中P（MMA‐2VN）链的数量。
The morphology of nanodomain structures in binary polymer blends of a random copolymer and a homopolymer is determined using electronic excitation transport (EET) studies. The experimental system employed is a copolymer, 6.5% atactic poly(methyl methacrylate‐co‐2‐vinyl naphthalene) [P(MMA‐2VN)], in atactic poly(vinyl acetate) (PVAc). The naphthalene groups serve as chromophores in the EET experiments. The mixtures are prepared such that initially the P(MMA‐2VN) chains are randomly distributed in the PVAc matrix. The nanodomains are formed while low‐concentration mixtures of the P(MMA‐2VN) in PVAc are held at constant temperature in the melt state (T≳T g ), above the temperature at which phase separation occurs. In the melt the chains diffuse, and P(MMA‐2VN) chains aggregate until the temperature is quenched below T g . The structures of the resulting domains are examined with time‐resolved fluorescence depolarization measurements, and the data are analyzed using an analytical theory to model EET among interacting polymer chains. The agreement between theory and data is very good. The results of the analysis indicate that the nanodomains correspond to aggregates with a characteristic size equal to the radius of gyration of the copolymer,R g . The number of P(MMA‐2VN) chains in aggregates prepared under different conditions is determined.