In this research,we observed PAMA(poly(n-alkyl methacrylate)) and PAA(poly(n-alkyl acrylate)¡^side chain crystalline.We find side chain is longer and crystalize more easily,melting point is higher.In the result of DSC thermograms,the length of side chain is 6 carbons,we can't find any thermal transition.But the length of side chain is 12¡B18 carbons,we only found Tm.In PLM observation,we only get side chain crystalline's picture,and can't see any liquid crystalline yet. Although in X-ray's illustrative can find layer structure's diffraction peak,but i think this evidence can't prove the system that is liquid crystalline.It just can be said that the layed structure was formed by side chain crystallization.

The polyglutamate which grafts with flexible alkyl side-chain by ester exchange reaction is like rod-hairy molecule. The numbers of methylene group of side-chain and the graft-density affect the molecular packing of poly(gama-alkyl-L-glutamate)s. To be sure the correct chemical structure of poly(gama-alkyl-L-glutamate)s by Fourier transform infrared spectrometer (FTIR), and find out the graft-density of each sample by proton nuclear resonance spectrometer (1H-NMR). Phase behavior of poly(gama-alkyl-L-glutamate)s were studied via differential scanning calorimetry (DSC) and variable temperature x-ray diffraction (XRD).We combine the results from C. C. Hsu(24). When the side-chain length is long enough (m>10), side-chains will crystallize into a 3D hexagonal lattice. The results of DSC and XRD analyses show that the side-chain crystalline phase will melt at Tm1, where as a liquid crystalline (LC) phase transition exists at Tm2. Poly(gama-alkyl-L-glutamate)s with shorter side-chain (m<8) tend to form 2D hexagonal LC structure. On the other hand, longer side-chains (m>10) tend to give lamellar structure. The critical number of methylene group of side-chain between hexagonal and lamellar structure is between 8 and 10.