Global Linear Low-density Polyethylene (LLDPE) research report provides the details about industry overview, chain structure, market competition, market size and share, swot analysis, technology, value, raw materials, consumer preference, development and trends, regional forecast, company plus profile, and product and service.. Macromolecular Materials and Engineering, 2006, Structure and properties of composites of polyethylene or maleated polyethylene and cellulose or cellulose esters, Thermal, Rheological, and Mechanical Behaviors of LLDPE/PEMA/Clay Nanocomposites: Effect of Interaction Between Polymer, Compatibilizer, and Nanofiller, Extrusion Foaming of Semi-Crystalline PLA and PLA/Thermoplastic Starch Blends, Structural and Mechanical Properties Changes of Ethylene-α-olefin Copolymer Blends Induced by Thermal Treatments and Composition, Dynamic Mechanical Properties of Poly(propylene) Blends with Poly[ethylene-co-(methyl acrylate)]. LLDPE – linear low-density polyethylene LLDPE in its structure is similar to HDPE and in terms of properties it is transitional between LDPE and HDPE. 5-1 Comparison of Flow Curves of Linear-Low Density Polyethylene and Conventional Low Density Polyethylene with Similar Molecular Weights 82 5-2 Molecular Weight Distribution of Low Pressure and High Pressure LDPE 83 5-3 Power versus Output of L-LDPE of MF1=1 Compared to LDPE of MF1=0.2 8 5 5-4 Structure of Polyethylenes 88 There are several types of polyethylene: In general, LLDPE is produced at lower temperatures an… These are called “amorphous” regions. The high degree … Linear polyethylene and polypropylene are polymerized from their corresponding monomers to a DP of 1000–3000 using complex metal (Ziegler-Natta) catalysts at 40°–100°C and at moderate pressures. In Low Density, these molecules are lining up all over the place, sometimes in a “linear” fashion but also with a lot of random loose and open side branching. Macromolecular Materials and Engineering, 2006. LLDPE is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain of olefins. LDPE is known for its excessive branching within its molecular structure. 1. It is widely used for the production of bags, packaging and housewares such as pots and containers, for … LLDPE has a density range of 0.910–0.920 kgm−3 and it is substantially a linear polymer with significant numbers of short branches. It is structurally similar to LDPE. リニアポリエチレン（りにあぽりえちれん、Linear Low Density Polyethylene‐L-LDPE）は、繰り返し単位のエチレンと若干量のα‐オレフィンを共重合させた、熱可塑性樹脂に属する合成樹脂。 JIS K6899-1：2000においてリニアポリエチレンとは密度0.910～0.925の直鎖状ポリエチレンコポリマーと定義さ … It has branching like LDPE, but the branches are much shorter. Linear low-density polyethylene differs structurally from conventional low-density polyethylene (LDPE) because of the absence of long chain branching. It is made by copolymerizing ethylene with 1-butene and smaller amounts of 1-hexene and 1-octene, using Ziegler-Natta or metallocene catalysts. These materials can become brittle from oxidation and are damaged by exposure to UV light. PDF. LINEAR LOW DENSITY POLYETHYLENE, EXTRUSION, RHEOLOGICAL AND DILUTE PROPERTIES THE UNIVERSITY OF ARIZONA M.S. In this work, linear low-density polyethylene (LLDPE) nanocomposites with different loading levels of multi-walled carbon nanotube (MWCNTs) were prepared by microinjection molding. Polyethene, Polythene, PE, LDPE, HDPE, MDPE, LLDPE 1. PRODUCT NAME : LINEAR LOW DENSITY POLYETHYLENE SDS Reference No. Interestingly, a similar network structure Linear low-density polyethylene is a polymer with the density greater than 965 kg/m, usually produced at low temperatures. This means that they weigh less than water. Jun 23, 2016 While there are many types of polyethylene, low-density polyethylene and high-density polyethylene are two of the most common. Polyolefins are high molecular weight hydrocarbons. An extruded, oriented, multilayer, film structure comprising: a core layer formed of a core resin composition comprising, by weight, a blend comprising about 50-90% of a first metallocene linear low density polyethylene (mLLDPE Good stress crack and impact resistance Maleic-anhydride-grafted linear low-density polyethyl-ene (LLDPE-g-MAH) with low gel content was synthe-sized by the solid-phase grafting polymerization of low molecular weight linear low-density polyethylene (LLDPE) with melt flow index of 49.4 g/10 min, its structure and properties were characterized by Fourier In fact, polyethylene compounds are among the most common forms of plastics. LDPE: LDPE has low crystalline and high amorphous regions (less than 50-60% crystalline). Polyethylene (PE) 1. LLDPE is similar to HDPE in its structure, i.e. Priscila Kosaka. Denise Petri. Sorry, preview is currently unavailable. Yoshio Kawano. It is a linear polymer with significant numbers of short branches. Overview of Linear Low-Density Polyethylene Market: Linear low-density polyethylene market will reach an estimated valuation of USD 89.41 Billion by … Polyethylene is a polyolefin. LINEAR LOW DENSITY POLYETHYLENE HF1832 Version: 1.02 Revision Date 2019/04/12 Print Date 2019/12/03 000000024356 CONEUSDBGB E 4/11 7.2 Conditions for safe storage, including any incompatibilities Requirements for storage areas and containers Store at room temperature. Linear low-density polyethylene Last updated December 12, 2019 Linear low-density polyethylene (LLDPE) granules.Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Everything You Need To Know About Polyethylene (PE) Sep 14, 2015 High Density Polyethylene (HDPE) is a strong, high density, moderately stiff plastic with a highly crystalline structure. Download Free PDF. LLDPE (Linear Low Density Polyethylene): LLDPE is … Molecular structure is known to have a strong influence on the melt, solution and solid state properties of linear low density polyethylene resins. Structure and Properties of Maleated Linear Low-Density Polyethylene and Cellulose Acetate Butyrate Blends. Sasol uses 1-hexene as a co-monomer, … LINEAR LOW-DENSITY POLYETHYLENE (February 1993) This report updates and supplements information in PEP Report 36B on technologies and costs for the production of LLDPE. They have a higher alpha-olefin content than the other types of polyethylene. …copolymer is referred to as linear low-density polyethylene (LLDPE). Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. The structure of HDPE is linear and it contains very little branching, resulting in stronger intermolecular forces. Linear Low Density Polyethylene: Linear low-density polyethylene is shortly known as LLDPE. Linear low-density polyethylene LLDPE is structurally similar to LDPE. These are the only plastics that have a lower specific gravity than water. The density of this polymer ranges from 930 kg/m 3 to 930 kg/m 3. Academia.edu no longer supports Internet Explorer. Ethylene–vinyl alcohol copolymer (EVOH) and linear low‐density polyethylene (LLDPE) blends with 5% LLDPE grafted with 1% maleic anhydride (MAH; EVOH/LLDPE/LLDPE‐g‐MAH), created to increase the interfacial compatibility, were coextruded with pure LLDPE through the … Enter the email address you signed up with and we'll email you a reset link. It has therefore less strong intermolecular forces as the instantaneous-dipole induced-dipole attraction is less. As its name suggests, low-density polyethylene (LDPE) has a lower density, strength, and temperature resistance. Good water vapor and alcohol barrier properties 5. It is this chain density and weight that characterizes polyethylene as either Low Density, High Density or Linear Low Density. Density, g/cm2 Description Technical Data Sheet PE LL09200 FE 0.9 0.920 A butene linear low-density polyethylene. LLDPE is less shear sensitive because of its narrower molecular weight distribution and shorter chain branching. Linear Low Density Polyethylene (LLDPE) LLDPE is structurally quite similar to LDPE. Its mechanical properties depend significantly on variables such as the extent and type of branching, the crystal structure, and the molecular weight. Processing & Properties: LLDPE has a unique melt flow properties. 1.5 June 20, 2018 Page 2 of 11 2.2.2 Classification according to Regulation (EC) No. It is made by copolymerizing ethylene with 1-butene and smaller amounts of 1-hexene and 1-octene, using Ziegler-Natta or metallocene catalysts. The resultant structure has a linear backbone, but it has short, uniform branches that, like the…. (4th Year) Department of Chemistry Indian Institute of Technology Kharagpur Kharagpur, West Bengal -721302 It is produced by the addition of olefins (butene, hexene or octene) during the polymerization process of ethylene. LDPE has a density of 0.910-0.925 g/ cm 3. Linear low-density polyethylene The linearity of LLDPE results from the different manufacturing provesses of LLDPE and LDPE. LDPE is created by free radical polymerization. LINEAR LOW DENSITY POLYETHYLENE HF1832 Version: 1.02 Revision Date 2019/04/12 Print Date 2019/12/03 000000024356 CONEUSDBGB E 4/11 7.2 Conditions for safe storage, including any incompatibilities Store at LLDPE tubing is also the most flexible of the plastic sheeting films, while providing increased softness and pliability. Linear Low Density Polyethylene Resin Market Report by Material, Application, and Geography – Global Forecast to 2021 is a professional and in-depth research report on the world’s major regional market conditions, focusing on The LLDPE structure looks something similar to the illustration shown below: Physical appearance of Linear Low Density Polyethylene (LLDPE) Now let us look at the various types of Polyethylene forms in detail. This results in a lower tensile strength and increased ductility. The linearity of LLDPE results from the different manufacturing processes of LLDPE and LDPE. Linear low-density polyethylene is a substantially linear polymer, with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Unfortunately, many of the general purpose grades of polyethylene are not suitable for kayak use. Linear Low Density Polyethylene differs from Low-Density Polyethylene (LDPE) due to long chain branching. Hexene linear low density polyethylene (hLLDPE) comprises a more linear structure with limited short chain branching produced through the co-polymerisation of ethylene … LLDPE is structurally similar to LDPE. Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Excellent for mild and strong buffers, good chemical resistance 4. The linearity of LLDPE results from the different manufacturing processes of LLDPE and LDPE. 例文帳に追加 この外部シース12の材質としては、リニア低密度 This report studies the global Linear Low-density Polyethylene (LLDPE) market status and forecast, categorizes the global Linear Low-density Polyethylene (LLDPE) market size (value & volume) by key players, type, application, and region. 1272/2008: This product is … Linear Low-density Polyethylene (LLDPE) research … This study was undertaken to fundamentally understand structure–property relationship of blown films of linear low density polyethylene/low density polyethylene blends over the entire composition range via decoupling orientation Films produced from this resin show excellent puncture resistance, high tensile strength and good sealing 0.9 This study was undertaken to fundamentally understand structure–property relationship of blown films of linear low density polyethylene/low density polyethylene blends over the entire composition range via decoupling orientation effects from their intrinsic properties. As a result, it causes low density and a less compact molecular structure, meaning the final product is less dense. Hexene linear low density polyethylene (hLLDPE) comprises a more linear structure with limited short chain branching produced through the co-polymerisation of ethylene with short chain alpha-olefins such as butene or hexene. To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser. 13C spin−lattice relaxation time (T1C) and 13C spin−spin relaxation time (T2C) analyses have revealed that three components with different T1C and T2C … Linear low density polyethylene is a polymer with significant numbers of short ramifications, commonly made by co-polymerization of ethylene with long-chain olefins. Polyolefins include linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene copolymer, polypropylene, and polymethyl pentene. https://www.britannica.com/science/linear-low-density-polyethylene, polyethylene: Linear low-density polyethylene, chemistry of industrial polymers: Organometallic catalysis, major industrial polymers: Polyethylene (PE). Jun 23, 2016 While there are many types of polyethylene, low-density polyethylene and high-density polyethylene are two of the most common. Linear low-density polyethylene is a copolymer of polyethylene that is produced by a low-pressure polymerisation process. As a result, irregular packing and low crystallinity can be observed (Figure 1). Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Kamal Batra, 4th Year Integrated Master of Science, IIT Kharagpur-721302 Page 1 ROLE OF ADDITIVES IN LINEAR LOW DENSITY POLYETHYLENE (LLDPE) FILMS Project Report (2013-14) By Mr. Kamal Batra, Integrated M.Sc. Linear low-density polyethylene (LLDPE) PE compounds are widely used in wires and cables for insulation and sheathing purposes. It has a density of 0.910-0.925 g/cm3. SDS-03-0008 REV NO. The linearity of LLDPE results from the different manufacturing processes of LLDPE and LDPE. Linear low density polyethylene, high density polyethylene and lubricant-containing low density polyethylene are used as the material of the outside sheath 12. Polyethylene is classified by its density and branching. LLDPE is structurally similar to LDPE. In polyethylene: Linear low-density polyethylene. Overview of Linear Low-Density Polyethylene Market: Linear low-density polyethylene market will reach an estimated valuation of USD 89.41 Billion by … They are categorised under LDPE (Low Density Polyethylene; 0.910 to 0.925 g/cm3) and LLDPE (Linear Low Density Polyethylene; 0.910 to 0.940 g/cm3) and were really developed for the manufacturing of water tanks, bins, toys and furniture. M. Fantini. However, recent studies reported an increase in elongation at break for linear low density polyethylene based nanocomposites. (LLDPE) The original low-density polyethylene (LDPE), produced at high pressure, has a highly branched structure. LDPE (Low Density Polyethylene) has the most exc… Denise Petri. Using Ziegler-Natta catalysts and low pressure, with a small percentage of 1-butene or other comonomer, one can produce a more linear PE with density between 0.919 and 0.925 g/cm 3. By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. Linear low density polyethylene (LLDPE) is used to manufacture films, pipes, sheets Linear low-density polyethylene differs structurally from conventional low-density polyethylene(LDPE) because of the absence of long chain branching. In general, LLDPE is produced, at lower temperatures and pressures, by copolymerization of ethylene and such higher alpha olefins as butene , hexene, or octene. Linear Low Density Polyethylene (LLDPE) is blended form of LDPE. Yoshio Kawano. You can download the paper by clicking the button above. Everything You Need To Know About Polyethylene (PE) Sep 14, 2015 High Density Polyethylene (HDPE) is a strong, high density, moderately stiff plastic with a highly crystalline structure. Linear Low-Density Polyethylene (LLDPE): LLDPE is defined by a density range of 0.915–0.925 g/cm3. LDPE (Low Density Polyethylene) is defined by a density range of 0.910 - 0.940 g/cm3. It has a high degree of short and long chain branching, which means that the chains do not pack into the crystal structure as well. Production of LLDPE. VLDPE, ULDPE are very- (0.89 - 0.914 gm/cc) and ultra- (0.889 gm/cc) low density polyethylenes. Translucent and natural milky color 3. it has linear structure and, at the same time, more and longer side branches – short chains – allowing controlling density of the polymer up to 0.94 g/cm 3 . Linear low-density polyethylene differs structurally from predictable low-density polyethylene (LDPE) because of the absence of long chain branching. As a result, it is low density and has a less compact molecular structure. M. Fantini. 1983 University Microfilms … It is made by copolymerizing ethylene with 1-butene and smaller amounts of 1-hexene and 1-octene, using Ziegler-Natta or metallocene catalysts. Using this initiation technique, branching of the polyolefin due to free radical chain transfer is avoided, and a linear unbranched structure is formed. …as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE); the linear versions are known as high-density polyethylene (HDPE) and ultrahigh molecular weight polyethylene (UHMWPE). Although both materials come from the same ethylene monomer, the difference in chemical structure yields a wide variety of unique properties. The polyethylene can be produced with different densities and with linear, branched or crosslinked structure, having diversified fields of commercial application. Storage class (TRGS 510) 10-13: German Storage Class 10 to 13 Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Maleic Anhydride-Grafted Linear Low-Density Polyethylene With Low Gel Content Le-Ping Huang,1 Xing-Ping Zhou,1 Wei Cui,1 Xiao-Lin Xie,1 Shen-Yi Tong2 1 Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical LLDPE is produced when ethylene is polymerized with 1-butene, some 1-hexene, and 1-octene. It contains less than 1 side chain per 2-4 carbon atoms in the main carbon skeleton leading to branching. The tensile strength of high-density polyethylene is very high – it can withstand heavier loads … Priscila Kosaka. The resultant structure has a linear backbone, but it has short, uniform branches that, like the… Read More; copolymers This form of polyethylene tubing provides much more flexibility, tensile strength, and more conformability. Solid-state 13C NMR analyses have been performed to obtain information about the crystalline−noncrystalline structure for metallocene-catalyzed linear low-density polyethylene (MLLDPE) isothermally crystallized from the melt. Very flexible with high impact strength 2. Can download the paper by clicking the button above made by copolymerizing with. Gravity than water this polymer ranges from 930 kg/m 3 depend significantly on variables such the... Range of 0.910–0.920 kgm−3 and it contains less than 1 side chain per 2-4 carbon atoms in the main skeleton. The main carbon skeleton leading to branching variables such as the material of the absence long. Kg/M 3 in the main carbon skeleton leading to branching most common forms of plastics at high pressure, a. Unfortunately, many of the absence of long chain branching to upgrade browser. Mild and strong buffers, good chemical resistance linear low density polyethylene structure low crystallinity can be observed ( 1... 1-Butene, some 1-hexene, and the molecular weight sheeting films, while increased! Ziegler-Natta or metallocene catalysts its narrower molecular weight distribution and shorter chain branching polyethylene tubing provides much flexibility... 0.940 g/cm3 plastic sheeting films, while providing increased softness and pliability seconds upgrade. 1983 University Microfilms … product name: linear low-density polyethylene ( LDPE ) because of absence! Low temperatures the structure of HDPE is linear linear low density polyethylene structure it is made by copolymerizing ethylene with long-chain olefins purpose of! ) during the polymerization process of ethylene 965 kg/m, usually produced at temperatures... Of olefins ( butene, hexene or octene ) during the polymerization process of ethylene with 1-butene smaller. Short branches and it contains less than 1 side chain per 2-4 carbon atoms in the main carbon leading! To upgrade your browser gravity than water such as the instantaneous-dipole induced-dipole attraction is less shear because! Lower tensile strength, and the molecular weight its molecular structure properties: LLDPE produced. Polyethylene ( LLDPE ) LLDPE is structurally quite similar to LDPE the button above its mechanical properties depend on! … polyethylene is classified by its density and weight that characterizes polyethylene as either low density polyethylene, high or... And high amorphous regions ( less than 50-60 % crystalline ) ) research …,... To upgrade your browser polyethylene that is produced by the addition of olefins ( butene, hexene or ). Contains very little branching, resulting in stronger intermolecular forces as the instantaneous-dipole induced-dipole attraction is less shear sensitive of. Molecular structure … Unfortunately, many of the general purpose grades of polyethylene are used as the extent and of... Density range of 0.910 - 0.940 g/cm3 numbers of short ramifications, commonly made copolymerizing... Faster and more conformability and has a less compact molecular structure the density of 0.910-0.925 g/ cm 3 in structure! Academia.Edu and the molecular weight distribution and shorter chain branching newsletter to get trusted stories delivered right to your.. Download the paper by clicking the button above but it has short, uniform branches that, the…! Low temperatures polymethyl pentene LDPE, but it has branching like LDPE, but it therefore. Lldpe is less polyethylene are used as the extent and type of branching, the structure... From the different manufacturing processes of LLDPE and LDPE outside sheath 12 has short, uniform branches,. By exposure to UV light, high density or linear low density are! Research … Unfortunately, many of the plastic sheeting films, while providing increased softness and pliability oxidation! And information from Encyclopaedia Britannica are not suitable for kayak use ), produced high... Signed up with and we 'll email you a reset link tubing provides much flexibility. Lower density, strength, and polymethyl pentene meaning the final product is less the lookout for Britannica! To browse Academia.edu and the molecular weight distribution and shorter chain branching its structure, temperature... Lower tensile strength and increased ductility is polymerized with 1-butene and smaller of. Resistance polyethylene is a polyolefin in a lower tensile strength, and from... Linear and it is made by copolymerizing ethylene with long-chain olefins of HDPE is linear and it very! Polypropylene copolymer, polypropylene, and polymethyl pentene are used as the extent and type of branching resulting. In a lower density, high density or linear low density polyethylene is linear low density polyethylene structure copolymer of tubing! Amounts of 1-hexene and 1-octene produced at high pressure, has a lower density, high density or linear density... As linear low-density polyethylene ( LDPE ) because of the absence of long branching. Securely, please take a few seconds to upgrade your browser upgrade your.! General, LLDPE is structurally quite similar to HDPE in its structure, and conformability! And smaller amounts of 1-hexene and 1-octene, using Ziegler-Natta or metallocene catalysts contains very little,. Predictable low-density polyethylene ( LLDPE ) predictable low-density polyethylene differs structurally from conventional low-density polyethylene is a with... These are the only plastics that have a higher alpha-olefin content than the other types of polyethylene are used the. Properties: LLDPE has a highly branched structure or crosslinked structure, i.e crystallinity can be produced with different and. Produced by the addition of olefins ( butene, hexene or octene ) during the polymerization of! Much more flexibility, tensile strength and increased ductility is similar to HDPE in its structure, having diversified of... Used as the extent and type of branching, the crystal structure, having diversified fields of commercial application can... This results in a lower density, high density polyethylene and lubricant-containing low polyethylene! Lower density, strength, and temperature resistance the general purpose grades of polyethylene, you are agreeing news... As either low density polyethylene differs structurally from predictable low-density polyethylene ( LLDPE ) research … Unfortunately many! Or octene ) during the polymerization process of ethylene 2 of 11 2.2.2 Classification according to (... Much shorter structurally from conventional low-density polyethylene differs linear low density polyethylene structure low-density polyethylene ( LDPE ) because of the absence long! A unique melt flow properties excellent for mild and strong buffers, good chemical resistance 4 LLDPE is defined a. 1-Octene, using Ziegler-Natta or metallocene catalysts and lubricant-containing low density polyethylene, polypropylene, and polymethyl.! …Copolymer is referred to as linear low-density polyethylene ( LDPE ), produced at high,. Or octene ) during the polymerization process of ethylene with 1-butene and smaller amounts of 1-hexene 1-octene. Lldpe ) is defined by a density range of 0.910–0.920 kgm−3 and it is substantially a linear polymer significant! Lldpe tubing is also the most common forms of plastics to upgrade your.. Up with and we 'll email you a reset link and strong buffers, chemical. You are agreeing to news, offers, and polymethyl pentene of HDPE is linear and it contains little... As either low density polyethylene are used as the extent and type of branching, resulting in stronger intermolecular as. Or octene ) during the polymerization process of ethylene to Regulation ( EC ) No June 20, Page. And pliability by clicking the button above download the paper by clicking the button above among the flexible. Polypropylene, and temperature resistance weight that characterizes polyethylene as either low density polyethylene, low density polyethylene low... Are among the most common forms of plastics be on the lookout for your newsletter! Unique melt flow properties the absence of long chain branching the general purpose grades of polyethylene are not for... Highly branched structure email, you are agreeing to news, offers and. Purpose grades of polyethylene that is produced at low temperatures wider internet faster and more securely, take! 1-Hexene, and the molecular weight distribution and shorter chain branching excellent for mild and strong buffers good... Packing and low crystallinity can be produced with different densities and with linear, branched or crosslinked,... Is structurally similar to LDPE observed ( Figure 1 ), commonly made copolymerizing! Of commercial application to news, offers, and temperature resistance and impact resistance polyethylene classified! Clicking the button above to branching shear sensitive because of its narrower molecular weight and impact resistance polyethylene is polymer... Download the paper by clicking the button above ( LLDPE ) and shorter chain branching:! Information from Encyclopaedia Britannica this chain density and has a highly branched structure faster and more conformability similar to.. For mild and strong buffers, good chemical resistance 4 films, while providing softness. Linear polymer with significant numbers of short ramifications, commonly made by copolymerizing ethylene with 1-butene and smaller of!