PP-g-MAH增容PP/PA66共混物的形态结构和性能

用固相接技法制备了马来酸酐接枝改性聚丙烯(PP-g-MAH),研究了PP-g-MAH增容PP/PA66共混物的形态结构和性能。结果表明,未用PP-g-MAH增容的PP/PA66共混物是热力学不相容的海岛型两相结构,而用PP-g-MAH增客的PP/PA66共混物虽是两相结构,但分散相粒子尺寸大大减小,PP-g-MAH对PP/PA66共混物实现了反应性增容。与不含PP-g-MAH的PP/PA66共混物相比,PP-g-MAH增容的PP/PA66共混物的拉伸强度提高约10 MPa,弯曲强度提高约10 MPa,弯曲模量增加10％,缺口冲击强度和伸长率保持不变。     

PP-g-MAH增容PP／PA66共混物的形态结构和性能

用固相接枝法制备了马来酸酐接校改性聚丙烯(PP-g-MAH)，研究了PP-g-PMAH增容PP／PA66共混物的形态结构和性能。结果表明，未甩PP-g-MAH增容的PP／PA66共混物是热力学不相容的海岛型两相结构，而用PP-g-MAH增容的PP／PA66共混物虽是两相结构,但分散相粒子尺寸大大减小,PP-g-FMAH对PP／PA66共混物实现了反应性增容。与不合PP．rMAH的PP／PA66共混物相比，PP-g-MAH增容的PP／PA66共混物的拉伸强度提高约10MPa，弯曲强度提高约10MPa,弯曲模量增加10％,缺口冲击强度和伸长率保持不变。     

反应增容PP/PA 6共混体系的形态与性能

采用侧向注入增容剂和直接混合的方法制备了不同配比的聚丙烯(PP)/马来酸酐接枝聚丙烯(PP-g-MAH)/聚酰胺(PA) 6共混物.考察了侧向注入和直接混合2种增容方式对PP/PP-g-MAH/PA 6共混体系形态与性能的影响.结果表明:加入PP-g-MAH可以同时提高PP/PA 6共混体系的刚性和韧性,侧向注入的增容效果尤为明显.侧向注入PP-g-MAH (5 phr) 的复合体系拉伸强度较纯PP提高了23.6%;侧向注入PP-g-MAH (20 phr)的复合体系拉伸断裂应变大于1 000%;PP-g-MAH能有效改善PP/PA 6体系的相容性,提高两相界面结合力,降低分散相粒子尺寸,且侧向注入比直接混合的效果更显著.     

马来酸酐接枝物对PE/PA6共混物相容性的影响

采用熔融共混法制备了PP/PA6/POE-g-MAH和PP/PA6/PP-g-MAH共混物。通过扫描电子显微镜(SEM)、差示扫描量热(DSC)仪分析和力学性能测试研究了增容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和宏观力学性能的影响。结果表明,在PP/PA6共混体系中分别加入POE-g-MAH和PP-g-MAH不仅能显著改善两相界面的相容性,减小分散相的粒径,而且能使共混物的力学性能显著提高。当增容剂的用量为5份时,PP/PA6共混物有较好的综合力学性能。POE-g-MAH和PP-g-MAH增容PP/PA6共混体系非等温结晶行为的研究表明,POE-g-MAH和PP-g-MAH均能促进PA6对PP基体的异相成核作用。     

PP-g-MAH对PP/PA6共混物的增容作用

采用熔融接枝法,考察了单体和引发剂用量对聚丙烯(PP)/马来酸酐(MAH)接枝物接枝率的影响。将PP-g-MAH作为PP/尼龙6(PA6)共混物的增容剂,并利用SEM、XRD、DSC-TGA和万能试验机等测试手段对PP-g-MAH增容改性PP/PA6共混体系进行了研究。结果表明,PP-g-MAH接枝物对PP/PA6共混物具有良好的增容效果,PP结晶得到细化,共混物的力学性能和耐高温性能得到改善。     

接枝聚丙烯增容改性PP/PA合金性能的研究

用PP接枝物增容PP/PA6共混体系,观察分析了共混合金的形态结构特点,测试了共混物的力学性能.结果表明：单独加入PP-g-MAH,力学性能均呈现先升后降的趋势,峰值时拉伸强度比未加接枝物时可提高20%,弯曲强度比未加接枝物时提高了54%,冲击强度比不添加接枝物时提高了3.6%.添加PP-g-MAH对不同比例PP/PA6共混物力学性能的影响不同,固定PP-g-MAH用量为4%,PA6质量分数为30%时共混物的综合力学性能达到最好.用PP-g-MAH和PP-g-GMA两种接枝物共同作为相容剂加入到PP/PA6共混物中比单独使用一种的效果要好,拉伸、弯曲和冲击强度都得到显著的提高.由共混物的SEM照片可以看到,PP-g-MAH使分散相的粒径变小,分布均匀,界面相互作用加强,所以是PP/PA6共混物的有效增容剂.     

PP固相接枝马来酸酐增容PP／PA6研究

以高速搅拌器为反应器,利用聚丙烯(PP)粉料自身摩擦生热,制备出不同接枝率的聚丙烯固相接枝马来酸酐(PP-g-MAH);通过对熔体流动速率测定、差热分析以及偏光显微分析,研究了PP-gMAH对PP／聚酰胺6(PA6)共混体系的增容作用及其对共混体系力学性能的影响。结果表明:采用固相法制备的PP-g-MAH可以明显提高PP与 PA6的相容性,PP-g-MAH接枝率高(1．2％)增容效果好;添加固相接枝PP-g-MAH的PP／PA6共混体系的拉伸强度和冲击强度高于添加熔融接枝物的PP／PA6共混体系。     

PP-g-MAH和PP-g-GMA增容PP/PA6共混体系的研究

将自制的PP—g—MAH（聚丙烯接枝马来酸酐）及PP—g—GMA（聚丙烯接枝甲基丙烯酸缩水甘油酯）作为PP／PA6共混体系的相容剂，研究了加入聚丙烯接枝物后PP，PA6塑料合金的各种力学性能及形态结构。结果表明：在PP／PA6共混物中加入PP—g—MAH后，共混物的力学性能得到明显的提高．添加PP—g—MAH对不同比例PP／PA6共混物力学性能的影响不同；用PP—g—MAH和PP—g—GMA两种接枝物共同作为相容剂加入到PP／PA6共混物中比单独使用一种的效果要好。共混物的SEM照片表明。PP—g—MAH是PP／PA6共混物的有效增容剂。     

PP-g-MAH对聚丙烯/尼龙6共混体的影响

研究聚丙烯接枝马来酸酐相容剂对聚丙烯／尼龙6体系的增容作用;并讨论了PP-g-MAH对PP／PA6共混物的力学性能的影响。结果表明:PP-g-MAH能有效地增强PP／PA6共混体系两相界面的相互作用,改善PP和PA6的相容性,是效果较好的相容剂。     

接枝共聚物对聚丙烯/尼龙6共混物结构和性能的影响

采用4种接枝共聚物作为增容剂来提高PP/PA6共混物相容性.研究了不同类型接枝共聚物对PP/PA6共混物加工性能的影响,同时也探讨了接枝共聚物对PP/PA6共混物微观结构变化的影响.结果表明PP/PA6共混物为热力学不相容的海-岛型两相结构,接枝共聚物的加入改善了PP与PA6的相容性,使两相分散均匀,对PP/PA6共混物的性能具有一定的改善作用.     

聚丙烯催化合金组成与性能研究

利用国产齐格勒-纳塔催化剂在反应器中合成出了聚丙烯（PP）催化合金,并系统地研究了不同气相聚合压力以及气相单体组成比所合成的聚合物合金组成与性能的关系,结果表明,在反应器中直接合成出的PP催化合金具有非常高的常温冲击强度和低温冲击强度,且随着合金中乙丙共聚物含量的增加而增加,但其模量却随之下降;若控制合金中乙丙共聚物的含量不超过10%,则可使PP合金材料既具有较高的冲击强度又具朋较高的模量。     

高抗冲聚丙烯合金的研制

采用物理共混与化学反应（歧化）并用的方式制备新型ＰＰ韧性材料,在增容剂（ＳＢ）含量ｍ２％,化学反应物（ＮＸ）含量为ｎ２％的情况下,研制的８０ＰＰ／２０ＰＥ合金韧性材料的冲击强度和断裂伸长率比原ＰＰ分别提高９倍和３倍以上,而拉伸强度仅降低约１０％,合金力学性能基本满足汽车行业的需要。     

用聚丙烯粉料代粒料制塑料扁丝的探讨

概述了以聚丙烯粉料部分代替传统的聚丙烯粒料来生产塑料编织袋扁丝的新工艺，分析了捏合速度、挤出温度、弓板加热温度等因素对扁丝性能的影响。     

聚丙烯粉料生产中的质量控制

分析了间歇液相本体法聚丙烯生产中的质量问题 ,重点讨论了聚丙烯粉料生产中块料、黑料及降解料产生的原因 ,并提出预防措施     

聚丙烯粉料生产中的质量控制

分析了间歇液相本体法聚丙烯生产中的质量问题,重点讨论了聚丙烯粉料生产中块料、黑料及降解料产生的原因,并提出预防措施。     

聚丙烯水相悬浮热氯化

研究了等规聚丙烯(IPP)水相悬浮热氯化,考察了氯化时间和温度、IPP粒径、搅拌转速、通氯速率等条件对氯化反应的影响。发现氯含量随氯化温度的升高而增大,随IPP粒径的减小而呈线性增大;在IPP充分分散条件下搅拌和通氯速率对氯化几无影响。扫描电镜(SEM)照片显示,氯化反应首先发生在粒子表面,氯化产物将粒子表面孔隙填充,增加了氯向粒子内部扩散的阻力,致使粒子内部的氯化反应缓慢。     

FTIR quantitative characterization of chemically modified polypropylenes containing succinic grafted groups

The FTIR quantitative evaluation of grafting succinic anhydride onto polypropylenes is presented. It was done by correlating relative absorbance values obtained from IR spectra with grafting levels of the sample as determined by an improved traditional hot titration method. The results obtained seem to be valid for either atactic or isotactic modified polypropylenes and suggest a careful review about how this technique is usually used in the quantification of polar groups grafted onto polyolefins. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2837–2847, 1999     

Quiescent crystallization kinetics and morphology of isotactic polypropylene resins for injection molding. I. Isothermal crystallization

The quiescent isothermal crystallization kinetics of polypropylene was studied as a function of molecular weight (M_w), amount of ethene, and amount of maleic anhydride and acrylic acid grafting. Differential scanning calorimetry and polarized light optical microscopy were used to follow this kinetics. It was observed that the linear growth rate, G, decreased with the increase of M_w, but increased with the amount of ethene. In the grafted polymers, as the amount of grafting increased, G decreased. The fold surface free energy, σ_e, was found to increase with the increase in M_w. The heterophasic and grafted polymers had σ_e values higher than the homopolymers. All samples showed spherulitic morphology, except the acrylic acid-grafted polypropylene that showed axialitic morphology. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1159–1176, 1998     

聚丙烯在建材中的应用

综述了聚丙烯在建筑领域中应用,包括聚丙烯管材、聚丙烯土工布、聚丙烯纤维混凝土及其他制品在建筑材料中应用情况。     

Experimental verification on UCST phase diagrams and miscibility in binary blends of isotactic, syndiotactic, and atactic polypropylenes

Issues in blends of polymers of the same chemical repeat unit but with different tacticities were addressed by investigating on the phase behavior and interaction strength of binary blends of three polypropylenes of different tacticities, i.e., isotactic polypropylene (iPP), syndiotactic polypropylene (sPP), and atactic polypropylene (aPP) using polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Although blends of polypropylenes have been widely studied in the past, there are still on-going debates on true phase behavior (miscibility vs. upper critical solution temperature (UCST) or immiscibility). Except for several earlier theoretical predictions based on the Flory-Huggins mean field theories, UCST behavior had not been experimentally proven for blends of sPP/iPP or aPP/sPP, owing to interference from PP crystallinity. In addition, interaction strength of the blends of different tactic polypropylenes is yet to be established. Using the method of equilibrium melting points, the Flory-Huggins interaction parameter of the aPP/iPP blend was shown to possess a significantly negative value (χ₁₂ = −0.21), which proves that the blend is indeed miscible in the melted amorphous as well as semicrystalline states as previously reported in the literature. However, the interaction parameters for the sPP/iPP and aPP/sPP blends were found to be nearly zero (χ₁₂ = −0.02 and −0.0071, respectively, at T = 150-180 °C), indicating that the interactions in two blends are weak and that the corresponding phase behavior for them borders on immiscibility at ambient temperature. This study also utilized novel approaches in constructing UCST phase diagrams by separating the amorphous phase domains from the crystalline spherulites, yielding data plausible for experimentally determining the UCST in iPP/sPP blend vs. aPP/sPP blend.