易开口、高透明线性低密度聚乙烯的研制与应用

采用助剂配方后改性的技术方法,研制开发出生产易开口、高透明线性低密度聚乙烯(LL-DPE)的助剂配方体系。考察了自主研发的增透剂、有机和无机开口剂等助剂的不同质量比对LLDPE膜的光学性能和开口性能的影响;并且在LLDPE装置上实现了工业化应用。     

饮料瓶用透明PP专用料应用开发

剖析了国内外饮料瓶用透明聚丙烯熔体指数,乙烯含量。经过对原料、成核剂及其他助剂的筛选,确定以RF075为基础树脂,以成核剂、抗氧剂、分散剂为组分的透明专用料配方。叙述了各种助剂对雾度的影响以及加工条件对聚丙烯光学性能的影响。应用实验结果表明,该透明专用料适合饮料瓶加工工艺,所生产的饮料瓶符合用户要求。     

国内外高透明聚乙烯薄膜专用料生产技术现状

论述了聚乙烯薄膜雾度产生的机理和影响因素,综述了国内外聚乙烯生产企业和研究单位通过改变共聚单体类型、改变催化剂体系、优化助剂配方、优化加工工艺生产高透明聚乙烯薄膜专用料的方法,通过对比发现,优化助剂配方和优化加工条件生产高透明聚乙烯薄膜专用料,操作简单灵活,不需要对工业化生产装置做大的改动,是高透明聚乙烯薄膜专用料最容易工业化推广的方法,为高透明线性低密度聚乙烯(LLDPE)薄膜专用料的开发提供技术参考。     

透明低密度聚乙烯的生产与加工

在不改变装置聚合工艺条件下，采用助剂配方后改性的技术方法，通过添加自行研制的复合助剂体系，工业化生产了透明线型低密度聚乙烯专用料DFDAg042，专用料的雾度降至12％以下，膜的拉伸强度、断裂伸长率及落镖冲击强度均有所提高。在用户加工应用中，分别生产了4μm、8μm的农地膜，膜的力学性能完全满足国家标准要求，所生产的地膜的雾度在10％以下。     

LLDPE装置棚膜专用料DFDA9042的开发

通过调整聚合工艺条件,在造粒过程中添加自主研发的有机成核剂与无机成核剂复配的复合助剂,生产出高透明的棚膜专用料DFDA9042,产品雾度小于14%。经加工试验膜的透明性能提高,其他机械性能良好。     

瓶用透明PP专用料的研制

以不同牌号聚丙烯(PP)为基础树脂，通过添加成核剂及其他助剂制备了瓶用透明PP专用料。研究了基础树脂、成核剂种类与含量及其他助剂对PP透明性的影响。结果表明：共聚PP透明性优于均聚PP，高乙烯含量PP透明性优于低乙烯含量PP；HB系列成核剂的增透效果要优于Milleda3988等进口成核剂；随着成核剂含量增加雾度降低，当含量超过0．23％时，下降趋势变小且趋于稳定；其他助剂如分散剂B的加入提高透明性，硬脂酸钙的加入使透明性降低。DSC测试发现成核剂的加入使得PP结晶温度提高近20℃。经吹瓶实验，所研制专用料的加工性能、透明性以及瓶的强度、韧性均达到使用要求。     

聚丙烯透明改性的研究

实验研究了基体树脂、成核剂及其他助剂对PP透明性的影响.结果表明:共聚PP透明性优于均聚PP,进口 Milleda3988成核剂增透效果优于国产成核剂,且成核剂的适宜添加量为0.25%左右.以PPR为基体树脂,加入成核剂及适宜的分散剂等其他助剂,对PP进行共混改性提高其透明性,研究和生产出高透明的PP改性料.     

高透明棚膜专用线型低密度聚乙烯DFDA-9047的开发

通过研究线型低密度聚乙烯(LLDPE)树脂透明改性技术及机理,调整生产工艺条件,在LLDPE粉料挤出造粒过程中,添加透明复合助剂,开发生产了高透明棚膜专用LLDPE DFDA-9047。生产DFDA-9047时,装置运行平稳,生产过程中的熔体流动速率、密度变化不大,拉伸性能远好于未添加透明复合助剂的LLDPE DFDA-7047;用其吹塑的薄膜透光率、雾度(10.2%)、落镖冲击破损质量均好于用DFDA-7047吹塑的薄膜,其棚膜性能与用国内处于领先地位的同类产品DFDA-9085吹塑的棚膜相当。     

注塑级透明聚丙烯专用料的研制与生产

以均聚聚丙烯(PP)为基体树脂,通过添加成核剂制备了注塑级透明PP专用料。成核剂的加入．不但改善了PP的光学性能,而且提高了PP的刚性,在某种程度上改善了其加工性能。为降低生产成本和提高透明PP的性能,研制了复配成核剂体系,添加该成核剂生产的透明PP的各项性能均达到技术指标;并讨论了加工温度和树脂熔体流动速率对透明PP光学性能的影响。     

高透明线性低密度聚乙烯专用料的市场概况

综述了线性低密度聚乙烯(LLDPE)的国内外生产和应用状况,重点调研了国内高透明LLDPE薄膜专用料的牌号发展现状,并调查了国内薄膜生产企业及其产能信息,分析了国内市场对LLDPE的需求变化情况。综合来看,目前国内市场供应的高透明LLDPE专用料的牌号不多,高透明LLDPE专用料具有开发的潜力。     

成核剂YS-688改性抗菌PP薄膜的研究

以聚丙烯（PP）为基体树脂,改性载银磷酸锆为抗菌剂,YS-688（二苄叉山梨醇衍生物）为成核剂,制备抗菌剂母粒、成核剂母粒和抗菌PP薄膜,研究了成核剂改性抗菌PP薄膜性能。结果表明：经YS-688改性的抗菌PP薄膜,球晶尺寸减小,结晶密度增大,结晶温度提高;含0．9％改性载银磷酸锆和0.3％YS-688的PP薄膜,其拉伸强度（纵向／横向）51．16／31．88MPa,透光率88．8％,雾度2．9％,对金黄色葡萄球菌和大肠杆菌抗菌率为99．26％和99．57％,物理力学性能和抗菌性能优良。     

高透光增强线型聚乙烯的研究及应用

研讨了添加成核透明剂等对线型低密度聚乙烯(LLDPE)结构与性能的影响。发现添加成核透明剂后LLDPE的结晶结构均匀细密,光学性能与力学性能大幅度提高。用于农膜可使蔬菜增产 10 %。     

成核剂对LLDPE晶体形态及结晶行为的影响

借助原子力显微镜、偏光显微镜和差示扫描量热仪,研究了山梨糖醇类成核剂对线型低密度聚乙烯(LLDPE)晶体形态及结晶行为的影响。结果表明:随着成核剂用量的增加,LLDPE的晶体形态呈均一化,球晶尺寸逐渐减小;成核剂的加入导致了LLDPE结晶温度和结晶度的提高。     

新型α和β成核剂对PP结晶和力学性能的影响

在聚丙烯(PP)中加入两种新型成核剂:二苄叉山梨醇衍生物YS-688(α成核剂)和芳酰胺类化合物TMB-5(β成核剂),通过密炼–挤出的方法制备了PP/成核剂共混物材料。通过偏光显微镜、X射线衍射、差示扫描量热和力学性能测试研究了这两种成核剂对共混物结晶和力学性能的影响。结果表明,两种成核剂在适量时均能提高PP的结晶速率和结晶度,细化晶粒,且使晶体界面模糊,其中TMB-5具有较强的诱导PPβ晶成核的能力,当其质量分数为0.075%时,可使PP形成树枝状的β晶,而YS-688未改变PP的晶型,只生成了α晶。YS-688可提高共混物的拉伸强度,而TMB-5对共混物的拉伸强度影响很小;当两种成核剂质量分数均为0.075%时,共混物的韧性最好,相对于纯PP,PP/YS-688共混物的常温和–30℃缺口冲击强度分别提高了37.41%和12.76%,拉伸强度提高了11.11%;PP/TMB-5共混物的常温和–30℃缺口冲击强度分别提高了100%和55.41%。     

Study of nucleation activity and application of a nucleating agent to copolypropylene

The influences of nucleating agent content on crystallization peak temperature, crystallization curve shape, crystallization onset temperature, and crystallinity of a copolypropylene were studied in detail by differential scanning calorimetry. The results showed that crystallization onset temperature and crystallization peak temperature increased 17°C–22°C and 15°C–19°C, respectively, with increasing nucleating agent content. The behavior of the nucleating agent showed excellent efficiency. But the shape of the crystallization curve broadened with increasing nucleating agent content, and the crystallinity came to an extremum when the nucleating agent content was 0.2%. These results generally differed from those for crystallization of i‐PP by a nucleating agent. Modification of copolypropylene was studied by use of a nucleating agent, and the characteristics of the effects of the nucleating agent on copolypropylene were mastered. The results showed that the hardness of a copolypropylene improved observably. So the abrasion resistance of biaxially oriented polypropylene (BOPP) film for cigarette packaging was improved by adopting the modified copolypropylene as the skin‐layer heat‐seal material of BOPP film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:3915–3919, 2006     

Preparation and Properties of a Reactive Type Nonionic Surfactant Grafted Linear Low Density Polyethylene

Summary A reactive type nonionic surfactant, monostearic acid monomaleic acid glycerol diester (MMGD) was synthesized in our laboratory. Grafting-copolymerization of linear low density polyethylene (LLDPE) with MMGD was carried out by using β ray irradiation in air in a twin-screw extruder. Evidence of the grafting of MMGD as well as its extent was determined by Fourier-transformed infrared (FT-IR) spectroscopy. The effects of monomer concentration, reaction temperature and screw run speed on degree of grafting were studied systematically. The thermal behavior of LLDPE-g-MMGD was investigated by using differential scanning calorimety (DSC). Compared with neat LLDPE, the crystallization temperature (T_c) of LLDPE-g-MMGD increased about 3 °C, and the melting enthalpy (ΔH_m) decreased with increase of MMGD content. It showed that the grafted MMGD monomer onto LLDPE acted as a nucleating agent. The tensile properties and light transmission of blown films were determined. Comparing with neat LLDPE film, no obvious changes could be found for the tensile strength, elongation at break and right angle tearing strength of LLDPE-g-MMGD film. The wettability is expressed by the water contact angle. With an increasing percentage of MMGD, the contact angles of water on film surface of LLDPE-g-MMGD decrease monotonically. Accelerated dripping property of film samples was investigated. The dripping duration of LLDPE-g-MMGD film and commercial antifog dripping film at 60 °C were 52 days and 17 days, respectively.     

PS／LLDPE共混物光泽度的研究

用两步交联加工方法制备PS／LLDPE。采用二苄基山梨醇（DBS）作为LLDPE成核剂,在配方中加入LLDPE量的0.1％的DBS时,发现减小了LLDPE相的球晶尺寸,提高了PS／LLDPE的熔体指数,共混体的加工性能明显改善,使光泽度和力学性能均得到提高。     

DMDBS成核改性聚丙烯抗菌薄膜的研究

以二(3,4-二甲基二苄叉)山梨糖醇(DMDBS)为成核剂,油酸酰胺改性载银磷酸锆为抗菌剂,聚丙烯(PP)为基体树脂,制备了成核剂母粒、抗菌剂母粒和PP抗菌薄膜,并对PP抗菌薄膜的抗菌性能、光学性能及力学性能等进行了研究。结果表明:经DMDBS改性的PP抗菌薄膜,球晶尺寸减小,结晶密度增大,结晶温度提高;含0.2%DMDBS和0.8%改性载银磷酸锆的PP薄膜的纵、横向拉伸强度分别为49.92、33.42MPa,透光率为88.5%,雾度为3.0%,对大肠杆菌和金黄色葡萄球菌抗菌率分别为99.33%和98.35%。     

Surface modification of linear low‐density polyethylene film by amphiphilic graft copolymers based on poly(higher α‐olefin)‐graft‐poly(ethylene glycol)

In this article, a series of amphiphilic graft copolymers, namely poly(higher α‐olefin‐co‐para‐methylstyrene)‐graft‐poly(ethylene glycol), and poly(higher α‐olefin‐co‐acrylic acid)‐graft‐poly(ethylene glycol) was used as modifying agent to increase the wettability of the surface of linear low‐density polyethylene (LLDPE) film. The wettability of the surface of LLDPE film could be increased effectively by spin coating of the amphiphilic graft copolymers onto the surface of LLDPE film. The higher the content of poly(ethylene glycol) (PEG) segments, the lower the water contact angle was. The water contact angle of modified LLDPE films was reduced as low as 25°. However, the adhesion between the amphiphilic graft copolymer and LLDPE film was poor. To solve this problem, the modified LLDPE films coated by the amphiphilic graft copolymers were annealed at 110° for 12 h. During the period of annealing, heating made polymer chain move and rearrange quickly. When the film was cooled down, the alkyl group of higher α‐olefin units and LLDPE began to entangle and crystallize. Driven by crystallization, the PEG segments rearranged and enriched in the interface between the amphiphilic graft copolymer and air. By this surface modification method, the amphiphilic graft copolymer was fixed on the surface of LLDPE film. And the water contact angle was further reduced as low as 14.8°. The experimental results of this article demonstrate the potential pathway to provide an effective and durable anti‐fog LLDPE film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011