Synthesis And Application Of The Poly (Long Chain α-olefin) With Ultra High Molecular Weight

In this research work, synthesis and application of the poly (long chain α-olefin) with ultra high molecular weight, the copolymerization of long chain a-olefin and divinylbenzene (DVB) and the grafting copolymerization of homopoly(long chain α-olefin) and maleic anhydride by solution polymerization were studied.Firstly, poly (long chain a-olefin) with ultra high molecular weight was synthesized in a two-stage polymerization process. In the first stage, or the prepolymerization stage, the bulk polymerization of long chain a-olefin was conducted in a well-stirred reactor. A high-yield spherical Ziegler-Natta catalyst was used in the polymerization. Triisobutyl aluminium (TIBA) was used as cocatalyst. Diphenyldimethoxysilane (DDS) was used as the external donor. The polymerization temperature was 0²â„ƒ. After the pre-polymerization, the pre-polymer was transferred to a refrigerator or kept at room temperature where the polymerization was continuously carried out for a designed time. Influence of various factors, such as reaction time, catalyst, catalyst dosage, Al/Ti and reaction temperature, on the intrinsic viscosity and viscosity molecular weight of poly(l-octene), poly (1-dodencene) and poly (1-octene-co-1-dodecene) were investigated. The polymer above show fine drag reduction for crude oil. To some extent the poly(long chain α-olefin)with ultra high molecular weight should be fine drag reducer in oil transport pipeline.The copolymerization of long chain a-olefin and divinylbenzene (DVB) synthesized by spherical TiCl₄/MgCl₂ catalyst (DQ) was studied. Influence of various factors, such as the dosage of DVB, polymerization methods, ratios of monomer /catalyst and reaction temperature, on the copolymerization were investigated. The copolymer obtained was characterized by IR and ¹H-NMR to determine the chain structure. The results of extraction show that the copolymer was cross-linked slightly.The content of soluble part had reached 87.98 percent and the intrinsic viscosity about 14 dL/g,Its soluble part viscosity molecular weight of its soluble part was as high as three million , And therefore succeed in synthesizing the linear poly(long chain a-olefin-co-DVB) with little cross-linked and the ultra high molecular weight.The grafting copolymerization of homo-poly(long chain a-olefin) and maleic anhydride by solution polymerization using BPO as initiator was studied. Influence of various factors, such as reaction time, reaction temperature and the dosage of BPO, on the grafting degree of MAH were investigated. The grafting product obtained was characterized by IR and the measurement of water contact angle ,The graft copolymer was coated on the surface of LDPE film and effectively improved the hydrophilicity of the surface of LDPE film. To some extent the study had explored new applications of the poly(long chain a-olefin).