Trong quá trình kết mạng cao su bằng lưu huỳnh, việc sử dụng chất
xúc tiến đóng một vai trò quan trọng. Phần tài liệu dưới đây mô tả khái quát về
lịch sử hình thành và ưu khuyết điểm của các chất xúc tiến khác nhau.
…
Organic chemical accelerators were not used until 1906, 65 years
after the Goodyear-Hancock development of unaccelerated vulcanisation, when the
effect of aniline on sulfur vulcanisation was discovered by Oenslayer.
Aniline, however, is too toxic for use in rubber products. Its
less toxic reaction product with carbon disulfide, thiocarbanilide, was
introduced as an accelerator in 1907. Further developments led to guanidine
accelerators. Reaction products formed between carbon disulfide and aliphatic
amines (dithiocarbamates) were first used as accelerators in 1919. These were
and still are the most active accelerators in respect to both crosslinking
rates and extent of crosslink formation. However, most dithiocarbamate
accelerators give little or no scorch resistance and therefore cannot be used
in all applications.
The first delayed action accelerators were introduced in 1925
with the development of 2-mercaptobenzothiazole (MBT) and
2-mercaptobenzothiazole disulfide (or 2,2´- dithiobisbenzothiazole) (MBTS).
Even more delayed action and yet faster-curing vulcanisation became possible in
1937 with the introduction of the first commercial benzothiazolesulfenamide
accelerator. Further progress was made in 1968 with the introduction of
pre-vulcanisation inhibitor (PVI), N-cyclohexylthiophthalimide (CTP),
which can be used in small concentrations together with benzothiazole
sulfenamide accelerators.
…
Trích
đăng từ sách Rubber Curing Systems, R. N. Datta, Smithers Rapra Press, trang 5 – 6, 2002
Nguồn:
www.books.google.com.vn
(vtp-vlab-caosuviet)
