Heat Shrinkable Polymer Blends Based on Grafted Polyethylene and Chlorosulphonated Polyethylene (Part I)

Abstract

Blend prepared by melt mixing of thermoplastic material-elastomer have gained considerable attention in recent years. Heat shrinkability of the polymer which depends on elastic memory can be introduced into the system in the form of an elastomeric phase. The present study deals with the measurement of heat shrinkability of the blend of grafted polyethylene with CSM. Interchain crosslinking between grafted polyethylene and elastomer improves the shrinkability. Crystallinity of the polymer blends also affected by interchain crosslinking, thus affecting the shrinkability. Probable interactions of the rubber and plastic phase are confirmed by IR spectroscopy. Extraction of the elastomeric phase is restricted due to interchain crosslinking as confirmed by SEM study.     

Heat‐shrinkable polymer blends based on grafted low‐density polyethylene and polyurethane elastomer. Part I

Blends prepared by melt‐mixing of thermoplastic material‐elastomer have gained considerable attention in recent years. Heat‐shrinkability of polymer, which is dependent on elastic memory, can be introduced into the system in the form of an elastomeric phase. The present study deals with the measurement of the heat‐shrinkability of the blend of grafted polyethylene and polyurethane elastomer. Interchain crosslinking between grafted polyethylene and elastomer improves shrinkability. High‐temperature performance of the sample depends on the degree of interchain crosslinking. Probable interactions between the rubber and plastic phase are confirmed by IR spectroscopy. Extraction of the elastomeric phase is restricted due to interchain crosslinking as confirmed by SEM study. © 2000 Society of Chemical Industry     

On the Heat Shrinkability and Interchain Crosslinking of Blends Consisting of Grafted Ethylene‐Propylene Polymer and Polyurethane Elastomer

Blends prepared by melt mixing of thermoplastic materials/elastomers have gained considerable attention in recent years from the viewpoint of heat shrinkability. The present study deals with the measurement of heat shrinkability of the blends of grafted ethylene‐propylene polymer and polyurethane elastomer. The used grafting materials are acrylic acid, vinyltriacetoxysilane, and glycidyl acrylate. Interchain crosslinking between grafted ethylene‐propylene polymer and polyurethane elastomer improves the heat shrinkability. The high temperature performance of the sample is dependent on interchain crosslinking. From torque rheometry it was observed that the maximum amount of interchain crosslinking occurred in the sample containing glycidyl acrylate as grafting material. The probable interaction between rubber and plastic phase was confirmed by IR spectroscopy.     

Studies in interchain crosslinking and heat shrinkability of polymer blends consisting of grafted low‐density polyethylene and ethylene‐acrylic rubber

Blends prepared by the melt mixing of thermoplastic and elastomer have gained considerable attention in recent years. Heat shrinkability, which is dependent on elastic memory, can be introduced into the system in the form of an elastomeric phase. The present study deals with the measurement of heat shrinkability of the blends of grafted polyethylene and an ethylene acrylic elastomer. Interchain crosslinking between grafted polyethylene and elastomer improves the shrinkability. High temperature performance of the samples depends on interchain crosslinking. From torque rheometry it was observed that the maximum amount of interchain crosslinking was obtained in the sample containing acrylamide grafted LDPE. The probable interaction between the rubber and the plastic phase is confirmed by IR spectroscopy.     

接枝支链结构对聚乙烯多单体接枝共聚物结晶性能的影响

采用固相接枝法合成聚乙烯(PE)与甲基丙烯酸缩水甘油酯、苯乙烯、丙烯酸丁酯的固相接枝共聚物(PETM),利用差示扫描量热法、X射线衍射和偏光显微镜等测试手段研究了接枝支链对接枝共聚物的结晶过程的影响,并对接枝共聚物的X射线衍射峰进行分峰,计算接枝共聚物的晶胞参数。结果表明:接枝支链并没有改变PE的晶型,只是充当异相成核剂的作用并阻碍PE的晶体生长;受接枝支链影响,PE中存在不完善的结晶,PETM的结晶度比PE低。     

Speciality Polymer Blends of Polyurethane and Chlorosulfonated Polyethylene (S-cure)

Abstract

Blends of polyurethane (vibrathane- 5008 Uniroyal Co., USA) and hypalon (CSM-350 Du Pont, USA) prepared by three different blending techniques, have been studied, over the entire composition range. The processability of the polyurethane rubber was improved as a result of blending with CSM. The IR spectral analysis suggested that on heat treatment, without curatives, interchain crosslinking reaction occured between the two elastomeric phases. Experimental data revealed that, preheating of the preblends, before addition of curatives, enhanced the thermal properties of the blends. The degradation process were delayed along with the retardation in weight loss. The extractability of the single phase by solvent was also restricted on preheating, due to interchain crosslinking reaction.     

聚乙烯接枝改性及其与铝的粘结性

聚乙烯在过氧化二异丙苯存在下分别与丙烯酸，顺丁烯酸酐，顺丁烯二酸，顺丁烯二酸钠，丙烯酸羧丙酯，甲基丙烯酸环丙酯等单体熔融挤出，产物的红外光谱表明聚乙烯不同程度地接了各种极性基团。     

Multifunctional covalent and ionic coupling agents of maleic anhydride modified polyethylene

Amine and alcohol functional dendritic polymers were used as covalent coupling agents for maleic anhydride grafted polyethylene and their efficiency compared with metallic salt and zinc acetate, acting as an ionic coupling agent. The crosslinking reactions in the molten state were carried out at 150°C in an internal mixer and the resulting modified polyethylenes were characterized by dynamic mechanical analysis and Small angle X‐ray Scattering. These agents led to efficient coupling and crosslinking. The covalent coupling reactions were conducted in a heterogeneous multiphase system: The kinetics of crosslinking depends on the nature of the coupling agent: at 150°C, the reactions were completed within 5 min. with the amine hyperbranched polymer and 20 min. with the alcohol functionalized dendritic polymer. The zinc acetate forms ionic interactions with the grafted polyethylene in less than 1 min. Ionic interactions are thermo mechanically reversible; they correspond to electronic density fluctuations evidenced by SAXS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Lamination of high‐density polyethylene by bulk photografting and the mechanism of adhesion

The photolamination of high‐density polyethylene (HDPE) by bulk photografting is described, along with a discussion of the adhesion mechanism. HDPE can be photolaminated very easily with a thin poly(acrylic acid) layer, photopolymerized from acrylic acid, with very strong adhesion obtained after a short time of UV irradiation; the adhesion failure mode is polyethylene breakage. Thicker HDPE sheets require longer irradiation times for strong adhesion. Methacrylic acid or hydroxyethyl methacrylate provides no adhesion of HDPE at all after irradiation. When glycidyl acrylate is used alone between HDPE sheets, the peel strength of the photolaminated polyethylene is only approximately 320 N/m, but when glycidyl acrylate or hydroxyethyl methacrylate is grafted with acrylic acid, very good adhesion can be obtained. It is proposed that stronger adhesion is produced by a less branched grafted chain structure, which permits much more chain entanglement. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1097–1106, 2005     

PEW-g-MAH的制备及其对PP/Talc的改性

由线型低密度聚乙烯裂解反应制备了低相对分子质量聚乙烯蜡，考察了工艺条件的影响因素。得出了反应温度、反应时间与相对分子质量、熔点、软化点之间的关系。在锅中用熔融接枝法制备马来酸酐接枝聚乙烯蜡，研究了反应时间、温度、引发剂和马来酸酐用量对产物接枝率、接枝效率的影响。结果表明在引发剂质量分数0．1％、马来酸酐质量分数4％、反应温度150℃、反应时间3h的条件下，聚乙烯蜡的接枝率达到1.49％。接枝的聚乙烯蜡可作为一种新型偶联剂用于改性聚丙烯与填料复合材料的力学性能，使改性后的聚丙烯复合材料的悬臂粱缺口冲击强度提高了50％。     

Grafting of glycidyl methacrylate onto high‐density polyethylene with reaction time in the batch mixer

The melt grafting of glycidyl methacrylate (GMA) onto high‐density polyethylene (HDPE) in the presence of free radical initiators was investigated in the batch mixer. The graft content was determined with the titration and FTIR spectroscopy. The graft content increased with the increase of peroxide and initially introduced GMA concentration. Increase of the grafted GMA content resulted in decrease of the melt index. Interestingly, there was a sudden drop of GMA grafting content with the reaction time. It is assumed that depolymerization of GMA have taken place over the ceiling temperature. The crystallinity of the prepared glycidyl methacrylate grafted high density polyethylene (HDPE‐g‐GMA) was determined by the measurement of the heat of fusion. GMA grafted site acted as defect and crystallinity of the HDPE‐g‐GMA decreased with the increase of grafting reaction. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

硅烷交联可发泡聚乙烯材料的研究与应用

介绍硅烷交联可发泡聚乙烯材料的研制过程及生产工艺。着重阐述了聚乙烯经过硅烷接枝后对发泡成型的影响     

烷基化聚乙烯亚胺接枝SiO_x抗菌剂用于聚乙烯的性能

以纳米SiOx粉体为载体,通过共价接枝修饰,制备出烷基化聚乙烯亚胺接枝SiOx纳米抗菌剂,将其添加到高聚物中制备出抗菌聚乙烯(PE)塑料。实验结果表明:纳米SiOx粉体已经成功接枝上了有机高分子基团,添加3%这种抗菌剂制备的抗菌PE塑料对大肠杆菌和金黄色葡萄球菌的抗菌率都大于96%,达到了强抗菌效果,并且制备的抗菌PE塑料具有良好的抗菌长效性。     

Radiation‐induced grafting of glycidyl methacrylate onto high‐density polyethylene (HDPE) and radiation lamination of HDPE

Radiation‐induced grafting of glycidyl meth‐acrylate (GMA) onto high‐density polyethylene (HDPE) and the radiation lamination of HDPE by bulk grafting of GMA were reported. The effects of irradiation dose, monomer concentration, and atmosphere on grafting were investigated. The extent of grafting initially increased with irradiation dose and then remained almost constant. The extent of grafting was higher in 2M GMA than in 1M GMA at the same irradiation dose. The extent of grafting in nitrogen was higher than that in air. The grafted samples were characterized with FTIR spectrometry and thermogravimetric (TG) analysis. A carbonyl group was found on grafted HDPE samples, and the carbonyl index increased with the extent of grafting. TG analyses proved the existence of grafted materials on HDPE and the grafted GMA thermally decomposes at a temperature lower than that of HDPE. Strong adhesion could be obtained with radiation lamination of HDPE by bulk grafting of GMA. Benzophenone facilitates the grafting in a proper concentration range. The adhesion mechanism of the laminated samples was the entanglement of the grafted chains. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 772–779, 2005     

RAFT‐mediated graft polymerization of glycidyl methacrylate in emulsion from polyethylene/polypropylene initiated with γ‐radiation

The successful reversible addition‐fragmentation (RAFT)‐mediated graft polymerization of glycidyl methacrylate (GMA) in emulsion phase from polyethylene/polypropylene nonwoven fabric using 4‐cyano‐4‐[(phenylcarbonothioyl)thio]pentanoic acid under γ‐irradiation at ambient condition is reported. While conventional graft polymerization in emulsion phase yielded grafted materials with low of grafting (Dg) values [<7.5% at 10% (wt/wt) GMA], addition of RAFT agent to the graft polymerization system allowed the synthesis of polyethylene/polypropylene‐g‐poly(GMA) with more tunable Dg (8% ≤ Dg ≤ 94%) by controlling the grafting parameters. Relatively good control (PDI ～1.2 for selected grafting conditions) during polymerization was attained at 100:1 monomer‐to‐RAFT agent molar ratio. The number average molecular weight of free poly(glycidyl methacrylate) (PGMA) increased as a function of monomer conversion. NMR analyses of the free PGMA homopolymers indicate the presence of dithiobenzoate group from 4‐cyano‐4‐((phenylcarbonothioyl)thio) pentanoic acid on the polymer chain. The reactive pendant oxirane group of the grafted GMA can be modified for various environmental and industrial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45270.     

Thermal and mechanical properties of silane‐grafted water crosslinked polyethylene

The effects of linear low density polyethylene (LLDPE) grafting with vinyltrimethoxysilane by different types and contents of peroxide were studied. When grafting silane onto LLDPE, with 0.10 phr of Dicumyl peroxide (DCP) or 0.05 phr content of 2,5‐Dimethyl‐2,5‐di (tert‐butyl‐peroxy)‐hexane (DHBP), it was found that the grafting effect was improved; however, as Di(2‐tert‐butylperoxypropyl ‐(2))‐benzene (DIPP) or excess DHBP was used, LLDPE was supposed to cause self‐crosslinking, which reduced the grafting effect of silane and was invalid in the processing of extrusion. In this study, vinyl trimethoxysilane (VTMS) was grafted onto various polyethylenes (HDPE, LLDPE, and LDPE) using DCP as an initiator in a twin screw extruder. The grafted polyethylenes were able to crosslink utilizing water as the crosslinking agent. The effects of varied crosslinking time on the mechanical properties of the crosslinked polyethylenes were studied. It was found that the HDPE and LLDPE were apt to crosslink during the grafting process and thus decreased the grafting ratio. Multiple melting behavior was observed for crosslinked LDPE and LLDPE. Mechanical and thermal properties of the crosslinked PE are much better than that of uncrosslinked PE. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2383–2391, 2005     

聚乙烯改性的研究进展

综述聚乙烯的主要特性及分类,介绍聚乙烯的改性,包括填充、共混、接枝、交联以及改性后的应用情况,并指出今后聚乙烯改性的发展方向。     

高接枝率低凝胶含量的马来酸酐改性聚乙烯的制备

研究了亚磷酸二苯酯对马来酸酐接枝聚乙烯接枝率及凝胶含量的影响,发现其有很好的抑制交联的作用,在体系中添加亚磷酸二苯酯可以使产物的接枝率下降到0。同时研究了工艺条件对接枝物的影响,通过采用亚磷酸二苯酯并控制其投料时间,制备了高接枝率,低凝胶含量的接枝物。     

聚乙二醇双马来酸酯作交联剂制备高吸水性树脂的研究

用聚乙二醇双马来酸酯作交联剂制备高吸水性树脂。考察了交联剂的制备条件，以及交联剂链段的亲疏水性，树脂干燥温度和聚乙烯醇添加剂等对高吸水性树脂吸水性能的影响。实验表明，与聚乙二醇二丙烯酸酯比较，聚乙二醇双马来酸酯作为高吸水性树脂的交联剂具有制备简单，价格低廉等特点。     

LLDPE溶液接枝马来酸酐的研究

研究了在二甲苯溶剂中，以过氧化二苯甲酰（ＢＰＯ）为引发剂，线性低密度聚乙烯（ＬＬＤＰＥ）接酸酐的反应，采用正交实验方法考察了引发剂用量，单体及ＰＥ浓度。反应温度及时间、阻止交联剂的加入量等因素对接枝反应的影响。结果表明，各因素对ＰＥ接枝率影响的大小次序是ＭＡＨ用量，反应温度、阻止交联剂用量、ＬＬＤＰＥ浓度和ＢＰＯ有用量，阻止交联剂的加入可以有铲地防止ＰＥ恶性循环 自由基的交联。