نوع مقاله : مقاله پژوهشی
نویسندگان
دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Compared to block copolymer, random polypropylene copolymer has lower toughness and impact resistance, and this defect creates limitations in the use of this polymer in some applications, including in the pipe industry. Creating a beta crystal structure in random polypropylene with the help of nucleating agent is a well-known method to solve this weakness. To create a crystal structure, two types of nucleating agent were used: pre-synthesized pimelic acid nucleating agent and in-situ synthesis of pimelic acid during processing (0.2% by weight). Also, to increase the efficiency of germination, the addition of isotactic polypropylene (iPP) was used at the rate of 4% by weight. The samples needed for the tests were produced by compression molding method. Crystal structure evaluation was done by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods. Also, a transmission optical microscope (TOM) was used to examine the microstructure of the samples. Tensile and impact tests were used to check the mechanical behavior. According to DSC and XRD tests, it was observed that the sample made by adding 4% iPP has the highest amount of beta phase (67 and 72% respectively in each test). Microscopic images also clearly showed the collapse of the structure due to the increase in beta phase. Also, according to the purpose of the research, the mentioned sample showed a 100% increase in toughness compared to the pure sample.
کلیدواژهها [English]
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