Degradation Of LDPE LLDPE and HDPE In Film Extrusion

نویسندگان

  • Thorbjörn Andersson
  • Bengt Wesslén
چکیده

The degradation of different polyethylenes, LDPE, LLDPE, and HDPE, with and without antioxidants and at different oxygen concentrations in the polymer granulates have been studied in extrusion coating processing. The degradation was followed by On Line Rheometry, Size Exclusion Chromatography, Surface Oxidation Index measurements, and GC-MS Chromatography. The degradations starts in the extruder where primary radicals are formed which are subject the auto oxidation when oxygen is present. In the extruder, cross-linking and chain scission reactions are dominating at low and high melt temperatures, respectively, for LDPE, and chain scission is over all dominating for the more linear LLDPE and HDPE resins. Additives such as antioxidants react with primary radicals formed in the melt. Degradation taking place in the film between the die orifice and the quenching point is mainly related to the exposure time to air-oxygen. Melt temperatures above 280°C give a dominating surface oxidation, which increases with the exposure time to air between die orifice and quenching. A number of degradation products were identified, for example, aldehydes and organic acids, which were present in homologous series.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Heat-seal Strength Analysis of Laminated Films with Lldpe and Ldpe Sealant Materials in Bar Sealing Application

The heat-seal strength and failure modes of laminated films with Linear Low Density Polyethylene (LLDPE) and Low Density Polyethylene (LDPE) as the sealant materials were investigated. Heat-seal strength increases with platen temperature for all samples. The maximum achievable heat-seal strength for laminated film using LDPE and LLDPE as sealant material is 0.598 N/mm and 4.02 N/mm, respectivel...

متن کامل

Rheological study of heterogeneities in melt blends of ZN-LLDPE and LDPE: Influence of Mw and comonomer type, and implications for miscibility

It is estimated that 60 to 70% of LLDPE enters the market as blends (Utracki 1989a), primarily with other members of the polyolefin family, e.g., LDPE or polypropylene (PP). Despite the long history of polyethylene (PE) blending and its widespread use, many questions about the homogeneity of such blends, with obvious implications for thermodynamics and for the rheology, are still not answered t...

متن کامل

Implications of melt compatibility/incompatibility on thermal and mechanical properties of metallocene and Ziegler-Natta linear low density polyethylene (LLDPE) blends with high density polyethylene (HDPE): influence of composition distribution and branch content of LLDPE

In this paper, the implications of melt compatibility on thermal and solid-state properties of linear low density polyethylene/high density polyethylene (LLDPE/HDPE) blends were assessed with respect to the effect of composition distribution (CD) and branch content (BC). The effect of CD was studied by melt blending a metallocene (m-LLDPE) and a Ziegler-Natta (ZN) LLDPE with the same HDPE at 19...

متن کامل

Influence of Branching Characteristics on Thermal and Mechanical Properties of Ziegler–Natta and Metallocene Hexene Linear Low-Density Polyethylene Blends with Low-Density Polyethylene

The effect of the branch content (BC) and composition distribution (CD) of linear low-density polyethylene (LLDPE) on the thermal and mechanical properties of its blends with LDPE were studied. All blends and pure resins were conditioned in a Haake PolyDrive blender at 190°C and in the presence of adequate amounts of antioxidant. Two metallocene LLDPEs (m-LLDPE) and one Ziegler–Natta (ZN) hexen...

متن کامل

Rheological Study of the Miscibility of LLDPE/LDPE Blends and the Influence of Tmix

Blends of LLDPE and LDPE combine the favorable mechanical properties of the LLDPE with the ease of processing of LDPE. Yet, the melt rheological consequences of blending LLDPE and LDPE have received far less attention than have linear/linear or linear/ branched blends (1). Previous reports showed that blends of LLDPE/LDPE were either immiscible or partially miscible (2–5). Considering the compo...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004