MARC 主機 00000nam  2200349   4500 
001    AAI3383158 
005    20100910124355.5 
008    100910s2009    ||||||||||||||||| ||eng d 
020    9781109457339 
035    (UMI)AAI3383158 
040    UMI|cUMI 
100 1  Magwood, Leroy, Jr 
245 10 Evaluation of the physical property evolution of the 
       hybrid acrylate/epoxide photopolymerization system 
300    192 p 
500    Source: Dissertation Abstracts International, Volume: 70-
       10, Section: B, page: 6405 
500    Advisers:  Alec B. Scranton; Chris N. Coretsopoulos 
502    Thesis (Ph.D.)--The University of Iowa, 2009 
520    Hybrid acrylate/epoxide photopolymerizations offer a 
       number of advantages. Compared to each constituent 
       homopolymerization, the hybrid systems exhibit better 
       processing characteristics, reduced shrinkage, improved 
       physical properties, and lower sensitivity to both oxygen 
       and moisture. However these polymerization systems are not
       well understood and a systematic investigation of the 
       influence of the photosensitizer, the monomer structure 
       and final polymer morphology on the polymer structure and 
       physical property development has not been previously 
       reported. This thesis provides an improved fundamental 
       understanding of the relationship between the polymer 
       structure and physical property development for a spectrum
       of hybrid polymerizations systems of differing molecular 
       architectures. Four representative classes of hybrid 
       systems are examined: Case 1: A linear acrylate 
       polymerization followed by a crosslinking cationic 
       polymerization; Case 2: A linear acrylate capable of 
       adding into a crosslinked epoxide; Case 3: A single 
       monomer bearing both the acrylate and the epoxide 
       functionality which is capable of covalent bonding into 
       the epoxide network; Case 4: A crosslinking acrylate 
       followed by a crosslinking epoxide. Starting the 
       polymerization process with a linear free radical 
       polymerization (cases 1, 2, and 3) allows shrinkage to 
       occur without stress development (since the system can 
       flow to alleviate the stress) and may be used to produce a
       stage-curable system in which reaction system moves from a
       liquid monomer state, to a moldable putty state before 
       finally becoming a rigid polymer 
520    For each type of hybrid photopolymerization system 
       described above, the following studies were performed: the
       effects of the photoinitiator formulation on the 
       conversion profile of each constituent monomer were 
       characterized using  in situ FTIR; profiles of the storage
       modulus and tan delta were obtained as a function of the 
       temperature at varying compositions using DMA; the polymer
       morphology was characterized using SEM. In all cases, the 
       free radical polymerization occurred more rapidly than the
       cationic polymerization, and the relative rates were 
       influenced by the monomer composition and initiator 
       formulation. The mechanical property measurements and 
       microscopy studies revealed that the homogeneity of the 
       final polymer increases with a thermal post cure and with 
       the addition of a photosensitizer for some monomer 
590    School code: 0096 
650  4 Engineering, Chemical 
650  4 Engineering, Materials Science 
690    0542 
690    0794 
710 2  The University of Iowa 
773 0  |tDissertation Abstracts International|g70-10B 
856 40 |u