Molecular weight control

NOFMER® MSD

NOFMER® MSD is a suitable Chain Transfer Agent (CTA) for polymers containing styrene such as PS, AS polymers or SB latexes. In addition, NOFMER®MSD can be used as an addition agent with functions of a crosslinking co-agent and a retarder for LDPE crosslinking.

Feature of NOFMER®MSD

It works as a chain transfer agent (CTA) for PS, ASpolymers or SB latexes, etc.

It works as a crosslinking co-agent and a retarder for LDPEcrosslinking (XLPE)

It has less odor compared tomercaptans or other retarders (BHT etc).

Application

NOFMER® MSD is used in the production of coating materials as a CTA or covering of high–voltage electric cables as a crosslinking co-agent and a retarder.

In the point of view of the chain transfer constant, NOFMER® MSD is a suitable CTA because an excellent transfer constant should be between 0.01 and 1.0.
Furthermore, NOFMER® MSD can control low molecular weight and molecular weight distribution than NDM.
In addition, NOFMER® MSD can reduce molecular weight with increasing dosage, while keeping molecular weight distribution.

Technical Data

NOFMER® MSD can make a highly crosslinked polymer as a crosslinking co-agent at crosslinking temperature (180˚C). NOFMER® MSD has well balanced results in both torque value and scorch time.

NOFMER®MSD as a crosslinking co-agent and a retarder

Fig. Time-torque curve for LDPEcrosslinking

Molecular weight reduction

Table. Chain transfer constant (CTR)

Chain transfer constant	Ctr at 60˚C Monomer
St MMA	St	MMA
NOFMER®MSD	0.21	0.074
n-butylmercaptan (NBM)	22	0.67
t-butylmercaptan (TBM)	3.7	-
n-dodecylmercaptan (NDM)	14.8	-

Table. Polymerization of styrene

CTA		Mw × 10⁻⁴	Mw/Mn
None		32.1	2.8
NOFMER® MSD	0.5 wt%	11.1	2.8
	1.0 wt%	8.0	2.6
	2.0 wt%	4.9	2.6
n-dodecylmercaptan (NDM)	0.5 wt%	25.3	6.8
	1.0 wt%	26.4	11.0
	2.0 wt%	23.7	19.0

Table. Comparison data of NOFMER® MSD with other additives

Additives
Type		Amount (phr)	Max. torque(N.m)(180˚C)	Scorch time˟˟ (min) (145˚C)
-		-	0.3	6
NOFMER® MSD		1.0	0.45	17
Co-agent	TAIC*	1.0	0.44	3
Co-agent	TMPT	1.0	0.35	7
Retarder	BHT**	0.2	0.28	9
Retarder	2-Mercaptobenzothiazol	0.5	0.1	25

*TAIC: Triallyl isocyanurate, TMPT; Trimethylolpropane trimethacrylate
**BHT; 2,6-Di-t-butyl-p-cresol
˟˟Scorch time: Time to reach 10% of Max. torque at scorch-test temp (145˚C).

Molecular weight control

NOFMER MSD

NOFMER® MSD

Chain Transfer Agent

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