Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The influence of electron beam irradiation on the chemical and
  structural properties of medical grade Polyurethane   Thermo plastic polyurethane (TPU) provides excellent bio-compatibility,
flexibility and good irradiation resistance; however, extremely high
irradiation doses can alter the structure and function of macromolecules,
resulting in oxidation, chain scission and cross-linking. In this study, the
effects of e-beam irradiation on the medical grade thermo plastic polyurethane
were studied. The changes in the chain length and their distribution as well as
the changes in molecular structure were studied. The GPC (Gel Permeation
Chromatography) results show that the oxidative decomposition is followed by a
decrease in molecular mass together with an increase in polydispersity. This
indicates a very inhomogeneous degradation, which is a consequence of the
specific course and of the intensity of oxidative degradation. This was
confirmed by means of mechanical property measurements. Overall, this study
demonstrated that the medical grade TPU was affected by radiation exposure,
particularly at high irradiation doses.

36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ