| Liquid crystal (LC) polymers have some advantages, such as high modulus and strength and they were used widely as polymer composite materials. To the best knowledge, little research on LC nucleators of polypropylene is reported. It was significant to study on LC nucleators not only because it has important theory and science values, but it was also hopeful to synthesize high efficient and multifunctional nucleators on polypropylene.In this paper, seventeen new LC monomers were synthesized, which include, 4-(ethylbenzoyloxy)phenyl-4'-allyloxybenzoate (M1),4-allyloxybiphenyl-4'-ethylbenzoate (M2),4-(ethylbenzoyloxy)biphenyl-4'-allyloxybenzoate (M3),4-(ethoxybenzoyloxy)phenyl-4'-allyloxybenzoate (M4),4-allyloxybiphenyl-4'-ethoxybenzoate (M5),4-(ethoxybenzoyloxy)-biphenyl-4'-allyloxybenzoate (M6),4-allyloxybiphenyl-4'-[(p-ethoxybenzoyloxy)]benzoate (M7),4-(10-undecylen-1-yloxy)phenyl-4'-ethylbenzoate (M8),4-(ethylbenzoyloxy)phenyl-4'-(10-undecylen-1-yloxy)benzoate (M9),4-(10-undecylen-1-yloxy)biphenyl-4'-ethylbenzoate (M10),4-(ethylbenzoyloxy)biphenyl-4'-(10-undecylen-1-yloxy)benzoate (M11),4-(10-undecylen-1-yloxy)phenyl-4'-ethoxybenzoate(M12),4-(ethoxybenzoyloxy)phenyl-4'-(10-undecylen-1-yloxy) benzoate (M13),4-(10-undecylen-1-yloxy)phenyl-4'-[(p-ethoxybenzoyloxy)]benzoate (M14), 4-(10-undecylen-1-yloxy)biphenyl-4'-ethoxybenzoate (M15),4-(ethoxybenzoyloxy)-biphenyl-4'-(10-undecylen-1-yloxy)benzoate (M16),4-(10-undecylen-1-yloxy)biphenyl-4'-[(p-ethoxy-benzoyloxy)]benzoate (M17). The homopolymers P1～P17 were prepared by graft polymerization reaction with the corresponding monomer and PMHS, respectively. The copolymers PNA-1 and PNA-2 were obtained by the polymerization of M1, 4-allyloxy-4'-biphenylol (N1),4-allyloxybenzoic acid (N2) and PMHS. The chemical structures and mesomorphic properties of M1～M17, P1～P17, PNA-1 and PNA-2 were investigated by FT-IR spectronscopy,1H-NMR, polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, the influence of PNA-1 and PNA-2 to the crystallization properties and morphology of PP was dicussed with POM, DSC and X-ray diffraction (XRD).M1～M17 all exhibited nematic threaded textures, schlieren textures or droplet textures on heating and cooling cycles. In addition, M10 and M15 had exhibited fan-shaped textures of SA phase, broken fan-shaped texture and schlieren texture of SC phase, and mosaic textures of SB phase, respectively. M11 and M16 had exhibited batonnet textures of SA phase All the homopolymers and copolymers exhibited typical nematic textures.The clearing temperature (Ti) of M8 and M16 did not appeared on DSC curves due to thermal decomposition, but POM showed M16 exhibited nematic phase. M8 was monotropic LC monomers, and exhibited mesomorphic properties only on cooling cycle. DSC curves of all the homopolymers and copolymers showed glass transition temperatures (Tg). Moreover, P9, P11, P13 and P16 were semicrystallinity polymers and the others were non-crystallinity. Two copolymers exhibited both Tg and Ti. TGA showed that the temperatures at which 5% weight loss occurred (Td) were greater than 300℃for P1～P17 except P2, this indicated that these polymers had a good thermal stability.The blends PNA-1/PP and PNA-2/PP were obtained, and the results showed that PNA-1 in the blends could efficiently enhance the crystallization temperature and velocity. Moreover, PNA-1 could induceβ-form, and it had the best effect when the content of PNA-1 was 0.6% and the crystalline temperature was 110℃. The nucleation mechanism was believed that the crystal sheet grew as two-dimensional way. PNA-2 in the blends PNA-2/PP could markedly decrease the size of spherulite crystal forα-form PP and also enhance the crystallization temperature and velocity, and it had the best effect when the content of PNA-2 was 0.3%.
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