敏化辐射法制备高熔体强度聚丙烯的研究

以敏化辐射法制备了高熔体强度聚丙烯(HMSPP)，并研究了制备工艺与HMSPP结构性能的关系。研究结果表明，在普通聚丙烯中加入双官能度敏化剂SR213，再经60Co—γ射线辐射后，可以制得具有长链支化结构、微凝胶含量的高熔体强度聚丙烯。这种聚丙烯克服了普通聚丙烯熔体强度方面的缺陷，其拉伸、冲击等力学性能都有较大程度的提高，并且凝胶含量很小，能满足进一步成型加工的需要。     

高熔体强度聚丙烯的研究与应用现状

普通聚丙烯(PP)由于熔体强度低和加工温度范围窄,在热成型、挤出涂布和挤出发泡等领域应用受到限制。高熔体强度聚丙烯(HMSPP)具有较高的熔体强度,使聚丙烯可以在通用设备上熔相热成型、挤出发泡、挤出涂布,从而拓宽了PP应用领域。文章综述了国内外高熔体强度聚丙烯的研究进展和应用现状。     

高熔体强度聚丙烯的研究与应用现状

普通聚丙烯（PP）由于熔体强度低和加工温度范围窄,在热成型、挤出涂布和挤出发泡等领域的应用受到限制。高熔体强度聚丙烯（HMSPP）具有较高的熔体强度,使聚丙烯可以在通用设备上熔相热成型、挤出发泡、挤出涂布,从而拓宽了PP应用领域。综述了国内外高熔体强度聚丙烯的研究进展和应用现状。     

高熔体强度聚丙烯的研究应用进展

通用聚丙烯（PP）由于熔体强度低和加工温度范围较窄,因而在挤出发泡、挤出涂布和热成型等条件下难以加工成型,所以限制了通用聚丙烯的应用领域。高熔体强度聚丙烯（HMSPP）具有较高的熔体强度和优异的物理机械性能,因此拓宽了聚丙烯的应用范围。文章综述了国内外高熔体强度聚丙烯的性能特点、制备方法、研究进展和应用现状。     

高熔体强度聚丙烯研究进展

综述了国内外熔体强度聚丙烯（HMSPP）的研究进展和应用前景,重点介绍了为获得长链支化的高熔体强度聚丙烯一般采用的方法,如树脂掺混,射线辐射,化学交联和聚合过程中引发接枝等,并简述了国外高熔体强度聚丙烯在熔融热成型,挤出涂布和发泡等方面的应用。     

高熔体强度聚丙烯研究进展

相较于普通线型聚丙烯,高熔体强度聚丙烯(HMSPP)因其特殊的长支链结构,显示出优异的综合性能,可广泛应用于发泡、热成型、挤出涂覆、吹塑等领域,具有广阔的市场前景.本文对HMSPP的结构特征、生产方法、应用领域及研究现状等进行了概括总结.     

玻纤增强聚丙烯材料吹塑成型性能研究

采用双螺杆挤出机对不同熔体强度的聚丙烯树脂进行玻纤增强改性,制备了3种加工性能不同的玻纤增强聚丙烯材料.通过流变仪与熔垂法分别测试材料的熔体强度,并对这3种玻纤增强聚丙烯材料的吹塑成型性能进行了研究.结果 表明:提高材料的熔体强度有利于吹塑成型加工;熔体强度最大的1#样品的吹塑成型加工窗口较宽,在190～240℃内均能...     

高熔体强度聚丙烯制备的研究进展

高熔体强度聚丙烯(HMSPP)相比普通聚丙烯具有更优越的加工性能,因此也具有广阔的应用前景,成为许多国家近年来研发的热点。从制备方法方面总结了近年来提高聚丙烯熔体强度的研究概况,展望了HMSPP研究及应用的发展前景。     

用于发泡成型的高熔体强度聚丙烯的研究

在同向双螺杆挤出机上,对聚丙烯(PP)进行硅烷交联,制得高熔体强度聚丙烯(HMSPP),然后制备高发泡倍率的PP制品。分析了改性剂用量对PP熔体流动速率、熔体黏度、熔体强度、凝胶含量、力学性能、热性能和发泡性能的影响。结果表明:自制HMSPP的熔体强度和熔体黏度分别是纯PP的5.01倍和1.52倍,力学性能和耐热性与纯PP相比均有较大提高,可用于成型高发泡倍率制品。     

发泡用高熔体强度聚丙烯的研究

以过氧化苯甲酰(BPO)为引发剂,在同向双螺杆挤出机上对聚丙烯(PP)进行硅烷交联,制备了高熔体强度聚丙烯(HMSPP),然后制得高发泡倍率的PP制品.实验对改性PP的熔体强度、力学性能、热性能和发泡性能进行了表征.结果表明:自制HMSPP的熔体强度是纯PP的5.01倍,力学性能和耐热性与纯PP相比均有较大提高,可用于成型高发泡倍率制品.     

A new method for producing high melt strength polypropylene with reactive extrusion

A high‐melt‐strength polypropylene (HMSPP) was prepared using a twin‐screw reactive extruder from a commercial isotactic polypropylene through two stages, first, maleic anhydride is grafted to polypropylene to obtain a maleic anhydride‐grafted polypropylene (PP‐g‐MA), and then the grafted polymer is reacted with epoxy to extend the branched chain. Fourier transformed infrared spectroscopy indicated that maleic anhydride was grafted on polypropylene and reacted with epoxy. Melt flow rate and sag resistance test showed that the melt strength of the HMSPP improved considerably. Differential scanning calorimetry test showed that the long chain branches (LCBs) act as a nucleating agent in the crystallization of the HMSPP, which leads to a high crystallization temperature and crystallinity. Furthermore, the LCB efficiency of the HMSPP can also be calculated by analyzing its rheological property. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Characterization of high melt strength propylene/1-butene copolymer synthesized by in situ heat induction melt reaction

Propylene/1-butene copolymer powders were produced through bulk copolymerization of propylene with 1-butene in a 12 m³ polymerization reactor. High melt strength polypropylene (HMSPP) was synthesized by in situ heat induction melt reaction, in which pure propylene/1-butene copolymer powders without any additives were used as a basic resin and trimethylolpropane triacrylate (TMPTA) as a crosslinking agent. The structure and properties of the resultant HMSPP were characterized by means of various measurements. The content of TMPTA strongly influenced the melt strength and melt flow rate (MFR) of HMSPP. With increasing the content of TMPTA, the melt strength of HMSPP increased, and the MFR reduced. In addition, owing to the existence of crosslinking structure, thermal stability and tensile strength of HMSPP were improved compared with pristine propylene/1-butene copolymer. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

高熔体强度聚丙烯的研制

用过氧化物引发聚丙烯(PP)交联制备高熔体强度聚丙烯(HMSPP),研究了过氧化物的用量、反应温度、螺杆转速对HMSPP性能的影响。得到的HMSPP比普通PP的熔体强度提高约3倍。用所研制的HMSPP进行发泡实验,制得泡孔结构较均匀且闭孔的发泡制品。     

Structure and properties of high melt strength polypropylene prepared by combined method of blending and crosslinking

High melt strength polypropylene (HMSPP) was prepared by in situ heat induction reaction, in which pure polypropylene (PP) powders without any additives was used as basic resin, and low density polyethylene (LDPE) and trimethylolpropane triacrylate (TMPTA) were added as blending resin and as crosslinking agent, respectively. Microstructure of the obtained HMSPP (PP/LDPE/TMPTA blends) was characterized by FTIR, Wide‐angle X‐ray diffraction (WAXD), and testing of gel content. The effect of LDPE content on melt strength and melt flow rate of HMSPP were investigated. When the content of LDPE was 40 wt %, the melt strength of the HMSPP was above 16 CN, which was much higher than those of pure PP powder (2.6 CN) and PP/LDPE blends without TMPTA (6.1 CN). Moreover, thermal behavior and mechanical properties of the HMSPP were also investigated. The results showed that the thermal stability and impact strength of HMSPP were greatly improved. In addition, HMSPP possessed good processing performance and good foaming properties. The foams produced by HMSPP showed uniform, closed, and independent cells. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and foamability of high melt strength polypropylene based on grafting vinyl polydimethylsiloxane and styrene

A novel strategy was developed by melt grafting reaction in the presence of macromonomer vinyl polydimethylsiloxane (VS) and comonomer styrene (St) for preparing high melt strength polypropylene (HMSPP), and the rheological behavior, melt strength, and foaming ability of HMSPP were investigated. The results showed that VS and St were successfully grafted onto isotactic polypropylene (iPP), and the melt strength of HMSPP increased by more than 12 times compared to that of the virgin iPP. Moreover, HMSPP exhibited excellent foaming ability with smaller cell size, higher cell density, and higher expansion ratio compared to the virgin iPP when supercritical carbon dioxide was used as the blowing agent. POLYM. ENG. SCI., 55:251–259, 2015. © 2014 Society of Plastics Engineers     

化学改性高熔体聚丙烯的制备及其挤出发泡特性研究

以过氧化二异丙苯(DCP)为交联剂、三烯丙基异三聚氰酸酯(TAIC)为助交联剂,通过平行双螺杆挤出机制备了高熔体强度聚丙烯(HMSPP),研究了DCP用量对PP的流变性能、材料的热性能及发泡特性的影响。结果表明:DCP与TAIC配合使用能有效控制PP交联,从而制得有一定凝胶含量的HMSPP,同时材料的耐热性也得以提高,当DCP用量为0.8份,TAIC为3份时,制备的HMSPP,挤出发泡特性最佳。     

高熔体强度聚丙烯的研究进展

高熔体强度聚丙烯(HMSPP)因含有独特的长支链结构而具有较高的熔体强度和显著的应变硬化能力,极大的拓宽了聚丙烯的应用领域。文章围绕HMSPP的性能特点和三种国内外常用的制备方法对其研究现状展开综述。     

Polydimethylsiloxane assisted supercritical CO2 foaming behavior of high melt strength polypropylene grafted with styrene

Foamable high melt strength polypropylene (HMSPP) was prepared by grafting styrene (St) onto polypropylene (PP) and simultaneously introducing polydimethylsiloxane (PDMS) through?a?one-step?melt extrusion process. The effect of PDMS viscosity on the foaming behavior of HMSPP was systematically investigated using supercritical CO₂ as the foaming agent. The results show that the addition of PDMS has little effect on the grafting reaction of St and HMSPP exhibits enhanced elastic response and obvious strain hardening effect. Though the CO₂ solubility of HMSPP with PDMS (PDMS-HMSPP) is lower than that of HMSPP without PDMS, especially for PDMS with low viscosity, the PDMS-HMSPP foams exhibit narrow cell size distribution and high cell density. The fracture morphology of PDMS-HMSPP shows that PDMS with low viscosity disperses more easily and uniformly in HMSPP matrix, leading to form small domains during the extrusion process. These small domains act as bubble nucleation sites and thus may be responsible for the improved foaming performance of HMSPP.     

高熔体强度聚丙烯的开发及应用

综述了国内外高熔体强度聚丙烯的研究进展和应用前景，并简述了高熔体强度聚丙烯在挤出涂布和发泡等方面的应用。