Study On The Synthesis And Application Of A New Type PP Nucleator

Polypropylene(PP) has excellent integrated properties, such as nontoxic,relatively low density,able to endure erode,easy to process and excellent mechanical properties etc. And so, PP has become one of the most active varieties of synthetic resin. However, there are some limitations on PP itself, for instance, low transparency, low tensile strength and bad heat resistance etc., which have limited the range of application of the PP material to a great extent. In recent years, study and development on modified PP becomes the main direction of PP industry. Modification of PP by adding nucleators is one of the most effective and economic way to improve PP's properties. The transparency,the transmittance,tensile strength and flexural strength and the like. can notably be changed when nucleator are added to PP. In this work, a new type of PP nucleator (BX,DMBX,DCBX) whose structure is similar to dibenzylidene sorbitol nucleator, is synthesized with xylitol and benzaldehyde , p-methylbenzaldehyde , p-chlorobenzaldehyde as starting materials, and p-toluenesulfonic acid as the catalyst. The results show that the products have good stability in high temperature. Samples are prepared while pure PP (F401) was mixed with the products (0.1%～0.5%) and extruded. The properties of these samples are studied in this experiment. And the effects of this nucleator on the properties of PP and the effects of nucleator contents on the properties of PP were studied. The effects of nucleators on crystalline morphology of PP were also discussed in this article. The results show that adding DBX,DMBX and DCBX can improve greatly the mechanical and optical properties of PP . Especially, the effect is more obvious when DMBX and DCBX are added. 1. Nucleator can improve the transparency and transmittance of PP notably. The haze of PP decrease 46.8%, the transmittance increase 7.45% when nucleator contents are 0.3%. 2. Nucleator can improve the tensile strength and the flexural strength mechanical properties of PP and the crystallization temperature. The tensile strength of PP increase 8.0%, the flexural strength increase 11.2%, and the crystallization temperature improve 120.96℃from 109.8℃when nucleator contents are 0.3%. 3. The effects of nucleator on the properties of PP: The properties of PP can be obviously improved when the content of the nucleator increase from 0 to 0.3%. however, There are no more changes on PP mechanical properties when nucleator contents are more than 0.3%. 4. The effects of nucleators on crystalline morphology of PP: When nucleator contents are 0.3%, the nucleators, BX,DMBX,DCBX can decrease the diameter of PP crystal by 0.15mm to 0.1mm ,0.08mm ,0.07mm, respectively.