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The formation of primary crystals and their subsequent structural rearrangements are studied by real-time simultaneous small- and wide-angle X-ray diffraction using linear long-chain alkane C246H494 and a long alkane with a methyl branch in the center of the chain C96H193CH(CH3)C94H189. The initial crystals formed below the melting point of the folded chains are noninteger folded (NIF); this means that the layer period in the chain direction is l/p, where l is the extended-chain length and p is a noninteger (presently 1 < p < 2). Following their formation, the NIF crystals transform to the F2 “integer” form with all chains folded in two in the middle (p = 2). While this transformation is very rapid in the branched alkane, it is considerably slower in the linear alkane. From the electron density profiles across the lamellar stacks, it is calculated that the NIF form consists of a crystalline core of the same thickness as that in the once-folded F2 lamellae, but with an additional thick interlamellar amorphous layer containing long uncrystallized chain ends (cilia). In the initial NIF form, half the molecules are folded and fully crystallized. The others traverse the crystal layer only once and are only half-crystallized. It is suggested that the uncrystallized ends (cilia) of these latter molecules are generally too short to be incorported in the crystal and are uneven in length due to the longitudinally random chain attachment during crystal growth. The NIF → F2 transformation involves postcrystallization of the cilia as they reach a length of l/2 through chain translation. The rapid transformation in C96H193CH(CH3)C94H189 is believed to be due to the initial preference for “correct” chain attachment, with the branch at the lamellar surface, thus leaving the cilia of length l/2 suitable for incorporation into the F2 crystals.

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Latexes functionalized with isocyanate groups were prepared by carrying out the emulsion terpolymerization of dimethyl meta-isopropenyl benzyl isocyanate (TMI) with methyl methacrylate and n-butyl acrylate. The film formation of these latexes and the tensile properties of the resulting latex films were studied. The effect of TMI concentration on the film properties was investigated. The locus of the isocyanate groups in the latex particles was controlled by using different polymerization processes. The locus of the functional groups was found to greatly influence the tensile properties of the latex films. Triethyl amine was used as an external catalyst to cure the TMI polymer films. One-component self-curable systems capable of undergoing crosslinking at ambient temperatures were developed by incorporating small amounts of methacrylic acid into the recipe. These systems exhibited significant improvement in tensile properties upon curing. In addition, the shelf-stability of these latexes was found to be excellent.