分子筛负载有机磷酸酯成核体系对聚丙烯性能的影响研究

采用溶液浸渍法制备了不同分子筛负载有机磷酸酯（MBP）成核体系，研究其对等规聚丙烯（iPP）结晶性能和力学性能的影响，并通过扫描电子显微镜观察不同分子筛对MBP的分散情况，进而揭示不同分子筛负载MBP对iPP成核性能提升差异的原因。结果表明，B类分子筛?1和B类分子筛-2负载MBP对iPP性能影响有限。而A类分子筛-1和A类分子筛-2负载MBP成核体系对iPP的性能提升明显：不仅促使iPP的结晶温度分别提高了10 ℃和6 ℃；也在促使iPP的弯曲模量分别提高29.9 %和13.0 %的同时，使得其冲击强度分别提升8 %和7 %，起到了有效的刚韧平衡的作用。成核体系的SEM结果表明，A类分子筛-1的加入能有效分散MBP，从而促使其在iPP当中发挥成核性能；而B类分子筛?1本身团聚严重，无法很好地分散MBP，因此无法发挥提升iPP成核性能的作用。     

基于六氢邻苯二甲酸盐的α/β复合成核剂对聚丙烯性能的影响

将α成核剂六氢邻苯二甲酸钙和β成核剂六氢邻苯二甲酸锌复合得到α/β复合成核剂体系,研究了其对等规聚丙烯（iPP）力学性能和结晶性能的影响,并用Avrami理论研究了成核iPP的等温结晶动力学。结果表明,α/β复合成核剂以特定比例复合可以同时提高iPP的刚性和韧性,其中在复合比例为7∶3时,拉伸强度提升了6.7 %,弯曲模量提升了21.8 %,冲击强度提升了108.2 %。进一步研究了复合成核剂在iPP中的浓度效应,随着总添加量的增加,iPP的结晶温度逐渐增加,力学性能趋于稳定,在添加量达到0.4 %（质量分数,下同）时基本不变,此时冲击强度提升了175.3 %,弯曲模量提升了15.0 %,拉伸强度提升了6.5 %。等温结晶动力学的结果表明,复合成核剂体系的加入可以明显缩短iPP的结晶时间并且降低结晶所需的表面能。     

α/β复合成核剂对等规聚丙烯结晶形态的影响及非等温结晶动力学

采用偏光显微镜(POM)及示差扫描量热(DSC)法考察了3种α/β复合成核剂NA40/NABW、NA40/HHPA-Ba、NA40/PA-03对成核等规聚丙烯(iPP)的结晶形态及非等温结晶动力学的影响。对成核iPP结晶形态的研究结果表明：α/β复合成核剂的加入能够减小iPP的球晶尺寸。影响α/β复合成核剂成核iPP结晶形态的主要因素是ΔT_Cp（ΔT_Cp为成核iPP结晶峰值温度与iPP结晶峰值温度的差值）,即复合体系中ΔT_Cp较大的成核剂在iPP结晶过程中起主导作用,最终的结晶形态与单独添加这一成核剂时iPP的结晶形态相类似;当两种成核剂的ΔT_Cp接近相同时,两者竞争成核,成核iPP的结晶形态表现为两种成核剂共同作用的结果。因此,通过改变α/β复合成核剂的复合比例即改变两种成核剂的添加浓度,进而改变其ΔT_Cp,可以得到结晶形态完全不同的iPP。采用Caze法对非等温动力学进行了研究,结果表明：添加α/β复合成核剂能够提高iPP的结晶温度,缩短半结晶时间。复合成核剂成核iPP的结晶行为也同样受成核剂ΔT_Cp的影响,复合成核iPP的Avrami指数接近于复合体系中ΔT_Cp较大的成核剂单独添加时iPP的Avrami指数。     

Crystallization morphologies and non-isothermal crystallization kinetics of isotactic polypropylene modified by α/β compounded nucleating agents

采用偏光显微镜(POM)及示差扫描量热(DSC)法考察了3种α/β复合成核剂NA40/NABW、NA40/HHPA-Ba、NA40/PA-03对成核等规聚丙烯(iPP)的结晶形态及非等温结晶动力学的影响。对成核iPP结晶形态的研究结果表明：α/β复合成核剂的加入能够减小iPP的球晶尺寸。影响α/β复合成核剂成核iPP结晶形态的主要因素是ΔT_Cp（ΔT_Cp为成核iPP结晶峰值温度与iPP结晶峰值温度的差值）,即复合体系中ΔT_Cp较大的成核剂在iPP结晶过程中起主导作用,最终的结晶形态与单独添加这一成核剂时iPP的结晶形态相类似;当两种成核剂的ΔT_Cp接近相同时,两者竞争成核,成核iPP的结晶形态表现为两种成核剂共同作用的结果。因此,通过改变α/β复合成核剂的复合比例即改变两种成核剂的添加浓度,进而改变其ΔT_Cp,可以得到结晶形态完全不同的iPP。采用Caze法对非等温动力学进行了研究,结果表明：添加α/β复合成核剂能够提高iPP的结晶温度,缩短半结晶时间。复合成核剂成核iPP的结晶行为也同样受成核剂ΔT_Cp的影响,复合成核iPP的Avrami指数接近于复合体系中ΔT_Cp较大的成核剂单独添加时iPP的Avrami指数。     

辛二酸钙成核改性等规聚丙烯研究

研究了1种高效β晶型成核剂辛二酸钙(CaSu)的用量对等规聚丙烯(iPP)熔融、结晶行为和力学性能的影响。结果表明,CaSu为良好的β晶型成核剂,添加0.20%(质量分数)CaSu,β晶型含量可以达到84.02%;添加CaSu可以使iPP的成核能力增强,使其结晶温度增加;CaSu诱导iPP产生大量β晶型,同时降低了球晶的尺寸;添加CaSu可使iPP的缺口冲击强度、拉伸强度以及断裂伸长率提高,但弯曲模量降低。     

降冰片烯苄酰胺酸盐对等规聚丙烯力学性能和结晶性能的影响

采用差示扫描量热仪(DSC)和偏光显微镜(POM)考察了降冰片烯苄酰胺酸的不同金属盐在等规聚丙烯(iPP)中的成核效果,并研究了这些成核剂对iPP力学性能和光学性能的影响。结果表明,降冰片烯苄酰胺酸盐对ipp熔融峰值温度和结晶峰值温度的影响规律完全一致,降冰片烯苄酰胺酸钠盐(BHBC11)具有有较好的成核效果,添加浓度在0.2%时可使iPP的拉伸强度提高4.6%,弯曲模量提高18.6%;同时可使iPP的结晶峰值温度提高11.5℃;BHBC11的加入可以显著降低球晶的尺寸并大大缩短结晶时间;应用Caze方法对iPP和BHBC11成核iPP的非等温结晶动力学进行了研究,其Avrami指数都接近4。     

聚丙烯成核剂结构与成核性能关系的研究进展

添加成核剂是目前最简单有效地改性iPP的重要方法之一,在iPP的加工过程中,成核剂小颗粒均匀地分散或者熔解在iPP熔体中,为iPP结晶提供了大量的异相晶核,通过其更多的界面吸附iPP分子,降低了聚丙烯靠分子链自身运动团聚而成核结晶所需的活化自由能,加快了结晶速率,缩短了结晶时间,提高了结晶峰温度,改善了iPP的宏观力学性能。不同成核剂对聚丙烯性能的改善效果不一样,并且,具有不同晶体结构的相同或相似化学结构的成核剂也具有不同的成核效果。综述了聚丙烯用成核剂化学结构以及晶体结构与成核性能关系的研究进展,并对成核剂未来的发展方向提出了展望。     

抗老化透明聚丙烯的制备及性能

以有机磷酸盐成核剂(NA–11)作为等规聚丙烯(iPP)的透明添加剂,通过对分散剂、抗氧剂的优选,制备了抗老化性能优异的透明iPP材料。通过力学性能、雾度、透光率、热氧老化性能测试和DSC分析等手段研究了分散剂、抗氧剂协同作用对iPP/NA–11 (NiPP)材料力学性能、透明性能、结晶行为和抗老化性能的影响。研究结果表明,当乙撑双硬脂酸酰胺(EBS)作为分散剂时会影响NiPP材料的透明性,而聚乙烯(PE)蜡作为分散剂时NiPP材料的力学性能和透明性能保持较好。以聚乙烯(PE)蜡作为分散剂,添加抗氧剂1010的NiPP材料的抗老化性能优异,但是它的加入会恶化NiPP材料的透明性,NiPP材料的雾度增加了57.78%;添加复合抗氧剂B215的NiPP材料在保持透明性能的同时拥有优异的抗老化性能。NiPP/PE蜡/B215材料的雾度仅为15.0%,经过35d热氧老化后,NiPP材料的拉伸强度保持率为83.75%,弯曲强度保持率为81.36%,缺口冲击强度保持率为72.32%。     

长支链聚丙烯诱导β晶成核效应

利用乙烯基聚二甲基硅氧烷/苯乙烯接枝型长支链聚丙烯(PP-g-VS/St)在剪切和快速降温过程中可以诱导形成β晶聚丙烯这一优势,研究了PP-g-VS/St在注塑加工过程中作为高分子β晶成核剂对等规聚丙烯(iPP)结晶温度、晶体结构及力学性能的影响。结果表明改性聚丙烯的结晶温度、β晶相对含量和力学性能随着PP-g-VS/St添加量的增加而增加。当PP-g-VS/St的添加量为50%(质量分数)时,改性聚丙烯的结晶温度相对于纯iPP提高约10℃,β晶相对含量达32.8%,冲击强度、弯曲模量和拉伸强度分别相对于纯iPP提高了355.3%、53.8%和15.9%。这些结果为聚丙烯高分子β晶型成核剂的设计提供了新思路。     

两种羧酸盐成核剂的制备及其对聚丙烯的成核效果研究

合成了两种具有相似化学结构的聚丙烯（iPP）α晶型成核剂二环［2.2.1］庚⁃5⁃烯⁃2,3⁃二羧酸钠（NA₁）和二环［2.2.1］庚烷⁃2,3⁃二羧酸钠（NA₂）,研究了其在iPP中的成核效果。首先,利用差示扫描量热仪（DSC）和偏光显微镜（PLM）分别考察了两种成核剂对iPP结晶行为的影响。结果表明,当NA₁和NA₂的含量为0.3 %（质量分数,下同）时,iPP的结晶峰值温度分别提升了14.5 ℃和16.0 ℃。同时,两种成核剂都能够明显细化iPP球晶尺寸。其次,利用广角X射线衍射仪（WXAD）对成核iPP进行了表征,两种成核剂都诱导iPP产生了α晶型,说明均为α晶型成核剂。然后,对成核iPP的力学性能进行了表征。结果表明,随着两种成核剂用量的增加,iPP的拉伸强度和弯曲模量呈现先升高后平稳的趋势。当NA₁和NA₂含量为0.05 %时,成核iPP的拉伸强度较纯iPP分别提升了4.6 %和8.6 %,弯曲模量分别提升了8.2 %和21.7 %;冲击强度基本保持不变。     

Combined effect of organic phosphate sodium and nanoclay on the mechanical properties and crystallization behavior of isotactic polypropylene

Combined effect of α‐nucleating agent (NA) sodium 2,2′‐methylene‐bis(4,6‐di‐tert‐butylphenyl) phosphate (NA11) and nanoclay (NC) on the mechanical properties and crystallization behavior of isotactic polypropylene (iPP) was investigated by mechanical testing, wide‐angle X‐ray scattering (WAXD), differential scanning calorimetry (DSC), polarized optical microscopy (POM), and scanning electron microscopy (SEM). The mechanical testing results indicated that the separate addition of NA11 and NC only increased the stiffness of iPP while the combined addition of NA11, NC, and maleic anhydride grafted polypropylene (PP‐g‐MA) simultaneously improved stiffness and toughness of iPP. Compared to pure iPP, the tensile strength, the flexural modulus, and impact strength of iPP composites increased 9.7, 38.6, and 42.9%, respectively. The result indicated good synergistic effects of NC, NA11, and PP‐g‐MA in improving iPP mechanical properties. WAXD patterns revealed NA11, and NC only induced the α‐crystals of iPP. SEM micrograph showed that the PP‐g‐MA could effectively improve the dispersing of NC in iPP. Finally, the nonisothermal crystallization kinetics of neat iPP and PP nanocomposites was described by Caze method. The result indicated that the addition of NA overcame the shortcoming of low crystallization rate of NC nanocomposites and maintained the excellent mechanical properties, which is another highlight of the combined addition of NAs and nanoclay. Meanwhile, the result showed that nuclei formation and spherulite growth of iPP were affected by the presence of NA and nanoclay. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Nucleation effects of sodium and ammonium salts of 2,2′‐methylene‐bis‐(4,6‐di‐t‐butylphenylene)phosphate in isotactic polypropylene

The nucleation ability of isotactic poly(propylene) (iPP) to ammonium 2,2′‐methylene‐bis‐(4,6‐di‐t‐butylphenylene) phosphate (An) was investigated in the present work comparing with sodium 2,2′‐methylene‐bis‐(4,6‐di‐t‐butylphenylene) phosphate (NA‐11). Scanning electron microscope (SEM) revealed the crystalline morphology of both An and NA‐11 with planar surface characteristics. The observation of the fracture surface of nucleation iPP samples by SEM showed An particles were dispersed uniformly in polymer and had a better compatibility with iPP matrix than NA‐11 particles. Differential scanning calorimeter (DSC) showed that the melting temperature of An was 262°C significantly lower than that measured from NA‐11 group (above 400°C). Crystallization behaviors of iPP/NA‐11 and iPP/An were also investigated by DSC analysis, respectively. The results showed the crystallization peak temperature and the crystallinity of iPP/An were almost near to that of iPP/NA‐11. Furthermore, mechanical and optical properties of iPP were strongly improved in the presences of An and NA‐11. The flexural strength of iPP was elevated 34 and 35% and the haze value was reduced from 40.4 to 15.1 and 14.9% by the addition of 0.15 wt% NA‐11 and An, respectively. These results demonstrate that the nucleating agent of An described here is a good nucleating agent for the crystallization of iPP as well as NA‐11. POLYM. ENG. SCI., 55: 22–28, 2015. © 2014 Society of Plastics Engineers     

Mechanical and thermal characteristics and morphology of polyamide 6/isotactic polypropylene blends in the presence of a β‐nucleating agent

The mechanical and thermal characteristics and morphology of polyamide 6 (PA6)/isotactic polypropylene (iPP) blends (10/90 w/w) prepared with different processing procedures and incorporated with an aryl amide nucleating agent, a kind of β‐nucleating agent (β‐NA) for iPP, were investigated. The yield strength and flexural modulus of the blends decreased as β‐NA was introduced into the blends, whereas the impact strength and elongation at break improved. The crystalline structures of the blends closely depended on (1) the processing conditions and (2) competition between the β‐nucleating effect of β‐NA and the α‐nucleating effect of PA6 for iPP. Scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction were adopted to reveal the microstructures of the blends. At a low β‐NA content (<0.1 wt %), the α‐phase iPP dominated the blends, whereas the relative content of the β‐phase iPP increased remarkably when the β‐NA content was not less than 0.1 wt %. The processing conditions also showed profound influences on the supermolecular structures of iPP; this resulted in different mechanical properties of the blends. As for PA6, the crystallization behavior and crystalline structure did not exhibit obvious changes, but PA6 did play an important role in the epitaxial crystallization of iPP on PA6. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

原位添加α晶成核剂对高熔体强度聚丙烯性能的影响

采用过氧化苯甲酰(BPO)为引发剂,通过一步反应挤出法将接枝单体苯乙烯(St)和端乙烯基硅油(VS)接枝到等规聚丙烯(i PP)上制备高熔体强度聚丙烯(HMSPP),同时在制备过程中原位添加α晶成核剂S20或NA11,考察了两种不同的α晶成核剂对HMSPP的制备及其结晶性能、力学性能和发泡性能的影响。熔体流动速率和分子量分布的测试结果表明,S20或NA11的原位添加没有影响i PP接枝反应的进行;差示扫描量热研究表明,成核剂的加入可以有效促进HMSPP的成核结晶,消除了HMSPP结晶过程中的双结晶峰现象,但成核剂的加入对HMSPP的力学性能并无显著影响。S20或NA11的加入可以有效调控发泡样品的泡孔尺寸,使得泡孔直径从38μm增大到50μm以上,发泡倍率也分别从25倍增大到36倍和37倍。     

有机磷酸盐成核剂粒径对PP性能的影响

通过调控反溶剂法中的转速、反溶剂与溶剂配比、溶液浓度等条件制备了不同粒径的2,2’–亚甲基双(4,6–二叔丁基苯基)磷酸钠(NA–40)成核剂,考察了NA–40粒径对等规聚丙烯(i PP)力学性能的影响,并利用差示扫描量热(DSC)仪研究了NA–40粒径对i PP结晶性能的影响。结果表明,随着NA–40粒径的增加,NA–40对i PP力学性能的改善作用变弱。NA–40平均粒径为(17.7±2.2)μm时,i PP/NA–40–1的弯曲弹性模量、弯曲强度和拉伸强度与纯i PP相比,分别提高了44.5%,20.5%和8.3%,相应的缺口冲击强度有所降低;当NA–40平均粒径为(52.6±1.1)μm时,i PP/NA–40–4的弯曲弹性模量、弯曲强度和拉伸强度的增幅分别降至16.8%,2.3%和6.4%。在较低的降温速率下,NA–40粒径对结晶峰值温度(Tc)的影响不明显,提高降温速率对Tc的影响开始显现。用扫描电子显微镜观察NA–40形貌发现,NA–40呈棒状,加工过程影响NA–40粒径,但对NA–40形貌没有影响。利用偏光显微镜观察NA–40在i PP熔体中的分散性,粒径较小的NA–40能够均匀分散在i PP熔体中,而粒径较大的分散性差,大大降低了NA–40的有效成核浓度,影响了NA–40对i PP力学性能及结晶性能的改善作用。     

A highly active novel β-nucleating agent for isotactic polypropylene

A highly active novel β-nucleating agent for isotactic polypropylene (iPP), cadmium bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate (BCHE30), was found and its effects on the mechanical properties, the content of β-crystal, and crystallization behavior of iPP were investigated, respectively. The results show that the impact strength and crystallization peak temperature of nucleated iPP are greatly increased, while the spherulite size of nucleated iPP is dramatically decreased than that of pure iPP. The content of β-form of nucleated iPP (k_β value) can reach 87% with 0.1 wt% BCHE30. The Caze method was used to study the non-isothermal crystallization kinetics of nucleated iPP and the crystallization active energy was achieved by Kissinger method.     

Mechanical properties of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers

Mechanical properties of the isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, the poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. An increase in toughness of iPP with the elastomers was associated with a decrease in rigidity and strength. Mechanical performance of iPP increased more with acicular W than with spherical GB due to reinforcing effect of W. Comparing the (iPP/GB)/SEBS and (iPP/W)/SEBS composites having the separate microstructure, strength and toughness values of the iPP/GB and iPP/W composites increased more with SEBS‐g‐MA at the expense of rigidity due to the core‐shell microstructure with strong interfacial adhesion. Moreover, the iPP/W composite exhibited superior mechanical performance with 2.5 and 5 vol% of SEBS‐g‐MA because of a positive synergy between the core‐shell microstructure and reinforcing effect of acicular W. The extended models revealed that the elastomer and filler particles in the (iPP/GB)/SEBS and (iPP/W)/SEBS composites acted individually due to the separate microstructure. However, the rigid GB and W particles encapsulated with the thick elastomer interlayer (R₀/R₁ = 0.91) in the (iPP/GB)/SEBS‐g‐MA and (iPP/W)/SEBS‐g‐MA composites acted like neither big elastomer particles nor like individual rigid particles, inferring more complicated failure mechanisms in the core‐shell composites. POLYM. COMPOS., 31:1285–1308, 2010. © 2010 Society of Plastics Engineers     

PP/PE⁃LD/NX8000K高韧高透明材料的制备及性能研究

以聚丙烯（PP）为基体,低密度聚乙烯（PE-LD）和NX8000K成核剂为添加剂,通过熔融共混法制备了PP/PE-LD/NX8000K高韧高透明共混材料。采用差示扫描量热、X射线衍射、偏光显微镜、雾度测试仪和冲击试验机等仪器对共混材料的结晶行为、晶体形貌、透明性和力学性能进行了表征与测试。结果表明,PE-LD能阻碍PP结晶,使其结晶度降低,从而降低共混材料的雾度;PE-LD和PP共混能显著提升共混材料的韧性;当PE-LD的含量为50%（质量分数,下同）,NX8000K成核剂含量为0.6%时,PP/PE-LD/NX8000K的雾度为16.43 %,冲击强度为77.94 kJ/m²,雾度比纯PP降低45.18 %,冲击强度提高至纯PP的1 465 %。